Dissertation/Thèse

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2025
Thèses
1
  • JUSSARA ISA BRAGA PACHECO
  • .

  • Leader : CHRISTIAN COLLINS KUEHN
  • MEMBRES DE LA BANQUE :
  • CHRISTIAN COLLINS KUEHN
  • SARAH EL CHAMY MALUF
  • RAFAELA DINIZ SOUSA
  • Data: 28 févr. 2025
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  • Malaria, a tropical disease caused by Plasmodium spp. and transmitted by the female Anopheles mosquito, recorded 249 million cases in 2022, with high mortality, especially in tropical and subtropical regions. Treatment of the disease consists of the use of drugs that can be classified according to their chemical structure and mechanism of action. Among the classes of drugs, artemisinin and its derivatives have great therapeutic effects. However, treatment failures related to resistance to this drug raise concerns. Therefore, the objective of this study is to evaluate the in vitro and in silico antimalarial activity of compounds derived from naphthoquinones, called RM-12, RM-13 and RM-14. To this end, the growth inhibitory concentration was determined for 50% (IC50) of Plasmodium falciparum strain W2, the value of the cytotoxic concentration of 50% of the population in cells (CC50) against the HepG2 (hepatocarcinoma cell) and Vero (derived cell from monkey kidney), and the selectivity index (SI) was calculated. The cytotoxicity assays were complemented with the hemolysis test with human erythrocytes. Furthermore, the physicochemical and pharmacokinetic properties of the compounds were evaluated using in silico tools. The asexual form of P. falciparum W2 was used, revealed by the Sybr Green I fluorophore, from a 1:2 serial dilution of the compounds, with a final concentration of 200 µM. Tests to determine the CC50 value were obtained by the fluorophore resazurin. From the ratio between the CC50 and the IC50, the IS was calculated. The physicochemical properties and biological activities were evaluated using Osiris and Molinspiration software. In the in vitro study, the compound RM-12 showed an IC50 of 5.14 ± 0.5 µM and CC50 against the HepG2 cell of 32.33 ± 4.88 µM, with the IS of 6.3 and against the Vero cell presented a CC50 of 22.87 ± 6.11, with an IS of 4.44. The compound RM 13 presented an IC50 of 1.78 ± 0.46 and a CC50 of 221.25 ± 0.74 for HepG2 cells and a CC50 ≥ 450 for Vero cells, with an IS of 124.1 and ≥ 252, 8, respectively. In relation to compound RM 14, the IC50 was 10.77 ± 3.36 µM, the CC50 was 216.9 ± 2.12 µM for HepG2, with an IS of 20.1, and CC50 ≥ 450, with an IS ≥ 41.7 for Vero cell. The compounds did not show a hemolytic effect, even at higher concentrations. Based on the results obtained, it was concluded that the compounds RM-13 and RM-14 were more selective for the parasite. All compounds were active against the parasite, however, compound RM-12 showed greater toxicity in human cells. Therefore, it is observed that the compound RM-13 is the most active and possible candidate for other pre-clinical antimalarial trials.

2
  • MARIA GABRIELA SOUZA FANTIN
  • .

  • Leader : DHELIO BATISTA PEREIRA
  • MEMBRES DE LA BANQUE :
  • PABLO RAFAEL SILVEIRA OLIVEIRA
  • ANA CAROLINA RAMOS GUIMARÃES
  • DHELIO BATISTA PEREIRA
  • Data: 28 mars 2025
    Ata de defesa assinada:


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  • The COVID-19 pandemic has posed significant challenges to healthcare systems,
    highlighting the need for a better understanding of the factors influencing disease
    susceptibility and severity. While factors such as advanced age, male sex, and high
    body mass index are recognized as aggravating conditions, there remains variability
    in disease manifestation that is not yet fully explained. Previous genetic studies have
    identified polymorphisms associated with severe COVID-19 outcomes, but the
    representation of the Brazilian population in these studies remains limited. This study
    aimed to analyze genetic variants previously associated with COVID-19 in 64 capillary
    blood samples stored on filter paper. The comparison groups consisted of 41
    symptomatic individuals and 23 oligosymptomatic/asymptomatic individuals. DNA was
    extracted and analyzed by Mendelics using the BeadChip® Infinium Global Screening
    Array-24 version 3.0 (Illumina®) genotyping technology, which can identify 654,000
    SNPs per sample. In the data analysis, a total of nine samples did not meet quality
    criteria, resulting in a final genomic dataset of 55 samples from 34 symptomatic and
    21 oligosymptomatic/asymptomatic individuals. The initial screening included 108
    SNPs previously described in the literature as associated with infection risk,
    hospitalization, and COVID-19 severity. From this dataset, 17 SNPs were identified in
    the studied population. Data analysis was conducted using the GenomeStudio
    software, leading to the exclusion of nine samples due to unsatisfactory quality criteria,
    leaving 34 symptomatic and 21 oligosymptomatic/asymptomatic participants.
    Regarding demographic data, participants ranged in age from 14 to 79 years (mean
    age of 38 years; median of 34 years), with a predominance of females (64.7%). Clinical
    analysis indicated that symptomatic individuals had a higher frequency of cough
    (79.4%), fever (70.6%), headache (67.6%), and sore throat (61.8%), while fever and
    headache occurred in 22.2% of oligosymptomatic individuals. Regarding genetic
    analyses, the screened SNPs were located in the following loci: 1q21.3 (rs35154152),
    2p16.1 (rs1123573), 3p21.31 (rs2531743), 4p15.2 (rs16877005), 4q24 (rs13107325),
    6p21.1 (rs1886814), 6p21.32 (rs35122968), 9p21.3 (rs28368148), 9q34.2 (rs8176719
    and rs687289), 9q34.13 (rs505922), 11p15.5 (rs35705950), 19p13.2 (rs73510898 and
    rs34536443), 19p13.3 (rs2109069 and rs12610495), and 19q13.33 (rs1405655). The
    frequency distribution of the SNPs between the analyzed groups was not statistically
    significant, and thus, an Odds Ratio estimation for the risk alleles reported in the
    literature and the clinical outcomes of this study was not performed. These findings
    reinforce the need for broader genomic analyses to better understand the influence of
    genetic factors on the response to SARS-CoV-2 infection and potential genetic
    biomarkers for COVID-19 susceptibility.

Thèses
1
  • LEANDRO DO NASCIMENTO MARTINEZ
  • .

  • Leader : CAROLINA BIONI GARCIA TELES
  • MEMBRES DE LA BANQUE :
  • CAROLINA BIONI GARCIA TELES
  • ROBERTO RUDGE DE MORAES BARROS
  • SARAH EL CHAMY MALUF
  • GEISA PAULINO CAPRINI EVARISTO
  • PAULO RENATO RIVAS TOTINO
  • Data: 17 juin 2025
    Ata de defesa assinada:


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  • Despite advances in the field of malaria chemotherapy, this disease continues to claim the lives of thousands of people every year. Given this issue, the search for new antimalarial compounds becomes essential, as reports of resistance threaten and jeopardize the current therapeutic arsenal available for treating this condition. From this perspective, the bi-triazole compounds 7RJ and 10RJ (the focus of this study) are diversified chemical classes that, in previous studies, have already shown promising results in inhibiting the asexual and sexual forms of Plasmodium falciparum, and may support the development of a new antimalarial compound. Therefore, the objective of this study is to evaluate the in vitro, ex vivo, and in vivo antimalarial activity of two bi-triazole compounds against the asexual and sexual forms of malaria parasite. Initially, the bi-triazole was analyzed using computational software -OSIRIS, Molinspiration, and ADMETlab - for the determination of physicochemical, toxicological, pharmacokinetic, and pharmacodynamic properties, respectively. Subsequently, a combination assay of the bi-triazole with a reference drug was conducted to evaluate the potential synergistic, additive, or antagonistic effect. In parallel, the antimalarial activity of bi-triazoles 7RJ and 10RJ was confirmed against circulating strains of P. falciparum and P. vivax through ex vivo schizont maturation assays using patient samples. Then, an ookinete inhibition assay was performed on samples from patients infected with P. vivax. Finally, the most active and selective compound, 10RJ, was tested in vivo murine models using Plasmodium berghei. From the results, in silico predictions of physicochemical properties revealed that all compounds met Lipinski's and Veber's rules and may have great potential in the development of a future orally bioavailable drug. The following values were obtained for compounds 7RJ and 10RJ, respectively: LogP (0.46 - -0.015), LogS (1.54 - 1.69), polar surface area (98.60 - 98.60), hydrogen bond acceptors (7 for both), hydrogen bond donors (1 for both), number of violations (0), number of rotatable bonds (5), and volume (201.81 - 201.81). Among the pharmacokinetic predictions, in most parameters, both compounds showed satisfactory results. The values were as follows, respectively: Caco-2 cell permeability (low), volume of distribution (low), elimination clearance (low), acute oral toxicity (204.33 mg/kg - 187.58 mg/kg), half-life (low), plasma protein binding (low), blood-brain barrier permeability (all values were positive), Pgp inhibitor (positive and negative), Pgp substrate (all values were negative), drug-induced liver injury (all values were positive), and maximum recommended daily dose (all values were positive). Regarding the pharmacodynamic prediction results, only compound 10RJ was active in enzyme inhibition, which may guide future studies on its potential protein target. For the in vitro drug combination results, analysis of the fractional inhibitory concentration values allowed for an additive classification of compound 10RJ. As for compound sensitivity against circulating strains, values were within the variation range, close to IC50 values (P. falciparum: 7RJ - 6.85 μM; 10RJ - 7.65 μM; P. vivax: 7RJ - 1.85 μM; 10RJ - 2.45 μM) obtained for the W2 strain of P. falciparum for both compounds. Finally, the P. vivax ookinete inhibition results showed inactivity for compound 7RJ in these forms and a promising activity ≥ 66% for compound 10RJ at the highest tested concentration of 10 μM. The in vivo evaluation results of compound 10RJ against P. berghei in murine models demonstrated that the compound was not active at the maximum tested concentration of 20 mg/kg after 4 days of treatment. Based on the results presented, it is possible to infer that compound 10RJ was the most promising regarding the development of a potential antimalarial, with action against both asexual and sexual forms of Plasmodium spp. However, it is worth noting that specific modifications to the molecule’s chemical structure may be necessary to increase its bioavailability, always respecting its toxicity threshold.

2
  • FLAVIA GEOVANA FONTINELES RIOS
  • MOLECULAR SURVEILLANCE OF ARBOVIRUSES AND PROTOZOANS FROM CULICIDS ASSOCIATED WITH RIPARIAN VEGETATION IN THE URBAN AREA OF PORTO VELHO, RONDONIA

  • Leader : GENIMAR REBOUÇAS JULIÃO
  • MEMBRES DE LA BANQUE :
  • GENIMAR REBOUÇAS JULIÃO
  • TAMARA NUNES DE LIMA CAMARA
  • FLAVIA BARRETO DOS SANTOS
  • LÍVIA MEDEIROS NEVES CASSEB
  • NILDIMAR HONÓRIO ROCHA
  • Data: 4 juil. 2025
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  • Culicidae are the most important arthropod vectors in public health, as they are involved in the transmission of pathogens that cause viral and parasitic diseases that affect humans and animals. The blood obtained by mosquitoes during hematophagy has been used to detect pathogens that may or may not be transmitted by vectors (molecular xenomonitoring) and to identify host feeding preferences. Another tool used in pathogen surveillance is the FTA card with sugar bait, to detect them in saliva samples from vectors. This thesis aimed to (i) compare the abundance and richness of mosquitoes in riparian vegetation areas and in dwelling outdoors; (ii) evaluate whether the size of the riparian vegetation fragment affects the abundance and richness of mosquitoes; (iii) evaluate the possible circulation of pathogens (dengue virus, Zika, chikungunya, Mayaro, Oropouche, Plasmodium spp, and trypanosomatids) from female mosquitoes (iv) and in FTA cards; (v) verify the females' food source; (vi) produce and distribute educational material on insect vectors and disease prevention. Collections were made quarterly for two consecutive years, covering the rainy and dry seasons in ten locations with riparian vegetation in the urban area of Porto Velho, Rondonia, and in 30 associated outdoors. The sampling of the culicidae was performed using the electric aspiration technique for 15 minutes. In the laboratory, all mosquitoes were taxonomically identified, and the female mosquitoes were given an FTA card with a sugar solution. After being sacrificed, the mosquitoes were stored at minus -80°C for subsequent RNA/DNA extraction and analysis by real-time PCR (qPCR) or conventional PCR to detect the pathogens and verify the food source. Abundance and richness data were analyzed using generalized linear mixed models (GLMM), and the infection rate was estimated using the minimum infection rate (MIR). A total of 3,914 mosquitoes were collected, distributed among 11 genera (Aedes, Aedeomyia, Anopheles, Coquillettidia, Culex, Limatus, Mansonia, Psorophora, Trichoprosopon, Uranotaenia, and Wyeomyia) and 21 species. The most abundant species were Culex quinquefasciatus (73.93%), Aedes albopictus (8.91%), and Aedes aegypti (7.05%). The outdoor habitat had a higher abundance of mosquitoes (2,285 - 58.38%) compared to riparian vegetation (1,629 - 41.62%). However, riparian vegetation exhibited more mosquito species than peridomicile vegetation. Mosquitoes were significantly more abundant in the dry season compared to the rainy season; however, the dry season showed a significant difference with lower species richness. A non-significant trend was observed between the size of the forest fragment and the abundance of mosquitoes in both environments. We observed a significant correlation of more species in locations with larger forest fragments of riparian vegetation. The molecular analysis of 221 pools resulted in one positive sample for ZIKV (Ct: 37.20 - MIR: 1.08), containing two females of Ae. aegypti collected in riparian vegetation. Of the 95 FTA cards, ZIKV was detected in four cards offered to Ae. albopictus, Cx. quinquefasciatus, Psorophora albipes, and Psorophora ferox, collected in three locations and in both environments. The booklet “Insects of Medical Interest” was produced and distributed in dwellings (n = 266 booklets) and in six public schools (n = 576 booklets) near the riparian vegetation areas. The integration of vector surveillance with molecular surveillance can be useful for monitoring the occurrence of emerging and re-emerging pathogens, as well as for directing control and prevention methods. Furthermore, scientific dissemination and popularization activities are an important strategy for preventing disease-carrying insects, having a social impact that can increase the involvement of academia with society, as well as the community's contact with science.

3
  • ENMANUELLA HELGA RATIER TERCEIRO DE MEDEIROS
  • .

  • Leader : GABRIEL EDUARDO MELIM FERREIRA
  • MEMBRES DE LA BANQUE :
  • GABRIEL EDUARDO MELIM FERREIRA
  • VLADIMIR COSTA SILVA
  • ANTÔNIO MAURO REZENDE
  • JOSEPH ALBERT MEDEIROS EVARISTO
  • CAROLINE RICCE ESPADA
  • Data: 9 juil. 2025
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  • Cutaneous leishmaniasis (CL) is a disease caused by parasites of the genus Leishmania and is
    widely reported in tropical and subtropical regions worldwide. In Brazil, the incidence is high
    in the Northern region, with the state of Rondonia reporting approximately 1,000 new cases
    annually. The species Leishmania (Viannia) braziliensis is the main one associated with
    infection cases in the state and is known to harbor the viral endosymbiont Leishmania RNA
    virus 1 (LRV1). The presence of LRV1 has been linked to mucosal lesions in CL and to cases
    of therapeutic failure with pentavalent antimonials, whose active form is trivalent antimonial
    (SbIII). Preliminary results have shown no relationship between the susceptibility of L. (V.)
    braziliensis strains to SbIII and LRV1. One strategy to understand these aspects of parasite
    biology is gene expression analysis. Accordingly, 20 strains of L. (V.) braziliensis were
    selected, of which 10 were positive for LRV1. All strains were normalized in an in vitro
    infection model using THP-1 cell lines derived from human monocytes. Subsequently, an in
    vitro susceptibility assay of L. (V.) braziliensis to SbIII was performed. Susceptibility analysis
    was conducted using two methods: smoothing curves and the activity index (AI). In the
    smoothing curves, two groups of parasite susceptibility to SbIII were observed: (i) susceptible
    (8 strains) and (ii) less susceptible (12 strains), based on the density of L. (V.) braziliensis in
    response to the drug, compared to the reference strain. In the AI evaluation, only 2 of the 20
    strains were classified as susceptible to SbIII relative to the standard strain. This discrepancy
    highlights the greater sensitivity of the smoothing curve method to detect subpopulations of L.
    (V.) braziliensis with heterogeneous responses to SbIII, since the AI, a conventional method
    described in the literature, measures only the average parasite response to the drug.
    Furthermore, the viral endosymbiont LRV1 was associated with the in vitro susceptibility of L.
    (V.) braziliensis to SbIII after interaction with THP-1 cells. Following this, RNA sequencing
    (RNA-seq) was performed using the Illumina platform. The analyses identified 17 differentially
    expressed genes: 2 overexpressed and 15 underexpressed between the LRV1
    +
    and LRV1
    -
    groups.
    Between the susceptible and less susceptible groups, only 1 underexpressed gene was identified.
    Overall, these genes are associated with metabolic processes, signal transduction, stress
    response, intracellular transport, cell cycle, gene expression regulation, and DNA
    recombination/repair. RNA-seq also enabled the assembly of the first complete genomes of
    LRV1 from eight L. (V.) braziliensis strains from the Brazilian Amazon, two of which showed
    distinct viral variants. Therefore, it is concluded that there is intraspecific variability in the
    parasite’s susceptibility profile to SbIII after exposure to THP-1 cells, but again, without a
    relationship to LRV1. The presence of LRV1 and susceptibility to SbIII showed limited
    influence on the moleculares profiles of L. (V.) braziliensis. Detection of viral transcripts by
    RNA-seq opens new possibilities to investigate the presence of the viral endosymbiont in
    already published Leishmania transcriptomes. Regarding the phylogenetic clustering of LRV1
    viral sequences, an association with Leishmania species was observed, supporting the
    coevolution hypothesis. In view of the above, these studies are fundamental for understanding
    the biology of Leishmania and may contribute to the development of new prognostic and
    treatment strategies for CL.

4
  • ALEX AUGUSTO FERREIRA E FERREIRA
  • .

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • ANA PAULA LIGEIRO DE OLIVEIRA
  • ILKA BIONDI
  • JAIME RIBEIRO FILHO
  • JACQUELINE DE ALMEIDA GONÇALVES SACHETT
  • Data: 11 juil. 2025
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  • Snakebite envenomation, caused by the accidental injection of venom from
    venomous snakes into humans, is a serious public health issue, especially in tropical
    regions of developing countries. Each year, 5.4 million people suffer snakebites,
    resulting in 1.8 to 2.7 million envenomations. In Brazil, between 2010 and 2023,
    343,403 cases were reported, with the Northern region leading in notifications
    (124,055 cases). Among the four genera of venomous snakes in Brazil, the Bothrops
    genus is of significant medical interest, accounting for approximately 86% of
    snakebites. Within this genus, Bothrops jararacussu ranks among the species that
    cause the most incidents and inject the largest amounts of venom, leading to severe
    damage. Although antivenom is effective against systemic effects, it has limited
    efficacy against local damage. Given this context, the aim of this study was to
    evaluate the dynamics of the inflammatory and hemorrhagic processes following
    experimental envenomation with the P-I metalloproteinase isolated from Bothrops
    jararacussu venom, named BjussuMP-II. To this end, the experimental
    envenomation was conducted in the gastrocnemius muscles of male Swiss mice,
    weighing between 18 and 22 grams (divided into groups of 5 animals), through
    intramuscular injection of 50 μL of PBS or 50 μg of BjussuMP-II. After 30 minutes,
    treatments with antivenom, LED, or a combination of antivenom and LED were
    administered. Three hours later, blood and muscle samples were collected for
    myotoxicity assays, histological sections, RT-qPCR to evaluate microRNA-223 gene
    expression, and immunoenzymatic assays for IL-1β detection. Other groups of
    animals were used to evaluate rolling and adhesion in the vascular endothelium via
    intravital microscopy and to analyze the hemorrhagic process by inducing a halo on
    the dorsal skin. The results reaffirmed that antivenom therapy alone is not effective
    in treating the local damage caused by snakebites. In contrast, photobiomodulation
    with LED, whether alone or in combination with antivenom, was shown to reduce
    myotoxicity, tissue damage, leukocyte influx, the number of rolling or adherent
    leukocytes in the vessels of inoculated muscles, as well as hemorrhage on the dorsal
    skin. When applied alone, LED was able to reduce microRNA-223 gene expression;
    however, none of the treatments were effective in reducing IL-1β levels in vivo. It
    was concluded, therefore, that LED treatment, when applied alone, reduces
    myotoxicity, hemorrhage, tissue damage, and leukocyte influx into the tissues, while
    also demonstrating potential for reducing microRNA-223 in vivo. Furthermore, the
    combination of antivenom and LED proved to be equally effective.

5
  • HALLISON MOTA SANTANA
  • .

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • LUCILENE DELAZARI DOS SANTOS
  • SONIA APARECIDA DE ANDRADE CHUDZINSKI
  • LEONARDO DOS SANTOS CORRÊA AMORIM
  • EDUARDO LANI VOLPE DA SILVEIRA
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • Data: 20 oct. 2025
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  • In Latin America, snakebite envenomation is considered both an occupational and a
    neglected disease. Recent studies estimate that the number of snakebite incidents
    involving venomous snakes worldwide exceeds 420,000 annually, with approximately
    20,000 resulting in death. In Brazil, most envenomation cases are caused by snakes
    of the Bothrops genus, which comprises more than 60 species distributed across the
    country. While many of the systemic effects of snake venom are neutralized by
    antivenom therapy, local effects—such as myonecrosis, dermonecrosis, pain, and
    edema are not fully mitigated. One of the key protein classes responsible for triggering
    the severe local inflammatory response is snake venom phospholipases A₂ (svPLA₂s),
    which contribute to cytotoxic and myotoxic damage in tissues. Camelid hyperimmune
    serum contains antibodies that lack light chains, known as heavy-chain antibodies
    (HcAbs; IgG2 and IgG3), with a molecular weight of approximately 90 kDa. These
    antibodies contain a single antigen-recognition domain of the heavy chain, termed
    VHH or nanobody. VHH domains exhibit lower immunogenicity, enhanced tissue
    permeability, and greater resistance to pH and temperature variations, presenting
    biotechnological potential for use as therapeutic agents to complement conventional
    antivenom therapy. HcAbs from Lama glama were purified from hyperimmune serum
    obtained following immunization with the whole venom and phospholipases A₂ from
    Bothrops jararacussu venom (vBj). IgG purification was performed using A and G
    Sepharose columns. Yields of IgG1, IgG2, and IgG3 were approximately 4 mg/mL, 1
    mg/mL, and 200 μg/mL, respectively. An experimental treatment was subsequently
    conducted in Swiss mice (18-20 g), in which 7 μg of HcAbs were administered
    following intramuscular injection of 25 μg of vBj into the gastrocnemius muscle. Posttreatment
    blood samples were collected, and plasma was analyzed for biomarkers of
    muscle damage (creatine kinase - CK) and cytotoxicity (lactate dehydrogenase -
    LDH), both of which showed significant reductions compared to the envenomated,
    untreated group. Similarly, the cardiac damage marker CK-MB was significantly
    reduced. The marker for acute hepatic injury (aspartate aminotransferase - AST) also
    decreased significantly relative to the untreated control, whereas the marker for chronic
    liver injury (alanine aminotransferase - ALT) remained unchanged across all groups.
    To evaluate the local inflammatory response, the release of the cytokine IL-1β and the
    protein expression of the NLRP3 sensor component of the inflammasome complex
    were measured. IL-1β and NLRP3 were highly expressed in the muscle tissue of
    animals inoculated with vBj, however, a significant decrease was observed after
    treatment with HcAbs. Treatment with HcAbs proved promising, as it was able to
    reduce tissue damage in an experimental animal model of vBj envenomation,
    highlighting the importance of new therapeutic approaches as an adjuvant to
    antivenom therapy in snakebite envenomation.

2024
Thèses
1
  • MATEUS FARIAS DE SOUZA
  • Trypanothione reductase of Leishmania braziliensis as a molecular target for the prospecting of new inhibitors: In vitro and in silico evaluation of Gyroxin and Convulxin from Crotalus durissus terrificus as inhibitors

  • Leader : ANDREIMAR MARTINS SOARES
  • MEMBRES DE LA BANQUE :
  • ANDREIMAR MARTINS SOARES
  • ALDO RODRIGUES DA SILVA
  • LUIS ANDRE MORAIS MARIÚBA
  • Data: 22 févr. 2024
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  • The Trypanothione Reductase (TR) is a validated molecular target for the development of new inhibitors to treat diseases caused by Trypanosomatids. On another front, snake venom toxins, due to their structural and functional diversity, are important sources of bioactive molecules for the development of new drugs, including the treatment of diseases such as Leishmaniasis. In this context, the present study aims to analyze the interaction of toxins (Giroxin and Convulxin from Crotalus durissus terrificus) with the Trypanothione Reductase of L. braziliensis (TRLb) through in silico models and evaluate their inhibition through in vitro models. To achieve this, molecular docking between TRLb and toxins was performed using the ClusPro2.0 tool, and molecular dynamics were conducted using the GROMACS tool. Subsequently, the gene for TRLb was inserted into the pET 28(a+) vector and expressed in E. coli. The relative molecular mass and isoelectric point were determined by 12.5% one-dimensional and two-dimensional SDS-PAGE, and enzymatic activity was evaluated using colorimetric methods. The venom from Crotalus durissus terrificus was obtained from the LABIOPROT-FIOCRUZ-RO venom bank. It was fractionated by affinity chromatography on a Tricorn 10/20 column filled with Benzamidine-Sepharose resin (GE Healthcare). In the inhibition assays, the IC50 was calculated using the non-linear regression model in the GraphPad Prism program. As results, in silico assays indicated that Convulxin and Giroxin are capable of interacting with the enzyme's catalytic site, opening possibilities for further research in the field. TRLb was obtained with a high degree of purity, and its catalytic activity was preserved, with a molecular mass and isoelectric point consistent with those described in the literature. The purification of Giroxin from C.d.t resulted in three fractions, named 1, 2, and Giroxin, with electrophoretic profiling showing a single protein band with a molecular mass of approximately 30 kDa. Giroxin was used at different concentrations for the assessment of its inhibitory capacity, namely 5 μM, 1 μM, and 0.2 μM, resulting in a decrease in the catalytic activity of TRLb by 88%, 41.2%, and 18%, respectively.

2
  • MARCOS EDUARDO PASSOS DA SILVA
  • .

  • Leader : NAJLA BENEVIDES MATOS
  • MEMBRES DE LA BANQUE :
  • NAJLA BENEVIDES MATOS
  • ROBSON DE SOUZA LEÃO
  • IVSON CASSIANO DE OLIVEIRA SANTOS
  • Data: 23 févr. 2024
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  • Pseudomonas aeruginosa is among the main microorganisms causing Healthcare-Associated Infections (HAIs), standing out as an opportunistic pathogen in Intensive Care Units (ICU). The great urgency surrounding this species is due to the increasing number of strains resistant to the various antibiotics used in its antibiotic therapy, including carbepenems, which among conventional antibiotics are the main choice for the treatment of infections. In these terms, multiple resistance mechanisms are associated with P. aeruginosa, such as expression of genes encoding enzymes that inactivate or hydrolyze the antimicrobials, and virulence factors such as biofilm. Therefore, the aim of this study was to molecularly identify the mechanisms of resistance in isolates of P. aeruginosa from patients hospitalized and hospital environment of ICUs in Porto Velho/RO. The samples were collected between 2017 and 2018 from three public reference hospitals. Antimicrobial susceptibility testing was carried out by disk diffusion and molecular typing of the isolates by PFGE and MLST. A total of 216 isolates were obtained, of which 162 were from patients: Oral cavity (78); Tracheostomy (37); Axilla (24); Urine (11); Blood (6) and Wound secretion (6). Of the hospital structures there were 54: Sink (22); Faucet (19); Bed (11) and Floor (2). As for the resistance profile, the highest rate of non-susceptibility was to Imipenem with 33.7% and Meropenem with 29.6%. Of the susceptible isolates, 93% were susceptible to Polymyxin B and 89.3% to Piperaciclin-Tazobactam. The multidrug resistance (MDR) phenotype was presented by 30% of the isolates, 84.6% of which came from patients. As for the resistance genes, the highest prevalence was blaCTX-M with 38.8%, followed by blaTEM with 29.1% and blaGES with 13.9%. The presence of P. aeruginosa clones was observed in different sites of the same patient, as well as in hospital structures and patients, and in different hospitals carrying resistance genes. In addition, high-risk clones (ST111, ST235 and ST277) were found worldwide and four new STs were described in this study. Furthermore, these data serve as a warning of the risk of dissemination of this pathogen harboring resistance genes, which could have an impact on HAIs and public health problems.

3
  • VANESSA MODESTO CÂNDIDO
  • .

  • Leader : SORAYA DOS SANTOS PEREIRA
  • MEMBRES DE LA BANQUE :
  • DANIEL ARCHIMEDES DA MATTA
  • RITA DE CÁSSIA PONTELLO RAMPAZZO
  • SORAYA DOS SANTOS PEREIRA
  • Data: 28 mars 2024
    Ata de defesa assinada:


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  • The hepatitis delta virus (HDV) is highly pathogenic and is linked to the progression of serious liver diseases such as cirrhosis and cancer. HDV requires the presence of hepatitis B virus (HBV) for its replication and spread. An estimated 12 to 72 million people are infected worldwide with HDV. Despite high endemic indicators, infections caused by HDV represent a condition neglected by health services. The diagnosis of HDV has limitations due to the availability of inputs applicable to the detection and determination of viral infection. Aiming to produce relevant biotechnological resources for the purpose of detecting HDV infection, recombinant antigenic targets were developed from sequences of the delta antigen (HDVAg) of HDV genotypes I and III. The characterization of recombinant HDVAg (rHDVAg) was carried out and different variables were analyzed with a view to evaluating the application of this target for the indirect detection of HDV infections. To this end, serological assays were conducted to detect the presence of anti-HDVAg antibodies, using ELISA and a panel containing 170 serological samples. Of these, 66 sera were previously characterized by qRT-PCR, of which 46 were identified as seropositive for HDV and 20 as seronegative. Of these, 66 sera were previously characterized by qRT-PCR, of which 46 were identified as seropositive for HDV and 20 as seronegative. Likewise, to investigate possible cross-reactions, 104 samples previously characterized in relation to different viral infectious agents were used. Preliminary results from serological assays using rHDVAg-I and rHDVAg-III revealed a sensitivity of 53.66% and specificity of 90.0%, and a sensitivity of 95.7% and specificity of 90.0%, respectively. It was possible to demonstrate the effectiveness of rHDVAg-III in terms of its ability to specifically recognize infections caused by HDV. The partial data obtained in the enzymatic assays demonstrate that the product developed in this study has potential for diagnosing HDV. The phase I proof of concept demonstrated the ability to apply rHDVAg, for the purpose of developing diagnostic prototypes, which can comprise immunoenzymatic and chemiluminescent assays and constitute a rapid test device for detecting viral infection. Perspectively, it will be necessary to increase the number of samples tested from both endemic and non-endemic areas to complete the analysis comprehensively and advance to phase II of the study. It is important to highlight that the development of different diagnostic strategies with inputs of high sensitivity and specificity for the detection and/or screening of the rHDVAg antigenic target can assist in the prognosis and, with attention to preventing the evolution of the infection and reducing general costs related to complications. due to chronicity and will also allow attention to the patient in order to limit liver worsening caused by the HDV virus.

4
  • SUZANNE NERY SERRATH
  • .

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • BRUNA CAVECCI-MENDONÇA
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • LUCIANA LYRA CASAIS E SILVA
  • Data: 24 avr. 2024


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  • Animal venoms are an important source of proteins with high adaptability to the environment. Among these proteins is L-amino acid oxidase (LAAO), which has been studied due to its involvement in various physiopathological effects such as hemolysis, edema, hemorrhage, apoptosis induction, cytotoxicity, microbicidal activities, effects on platelets, and activation of human neutrophils. Exosomes, cellular nanovesicles, play vital roles in intercellular communication, including immune responses, and participate in some inflammatory physiopathological effects such as oxidative stress, which is the main response to neutrophil activation. Thus, this study investigates the impact of LAAO isolated from the venom of the snake Calloselasma rhodostoma (Cr-LAAO) on the release of exosomes from human neutrophils, including activation patterns, proteins identified in the vesicles, and their signaling pathways. Isolated human neutrophils were incubated with RPMI (negative control), PMA (500 ng/mL positive control), and Cr-LAAO (100 μg/mL). Size characterization was performed using dynamic light scattering with the Zetasizer Nano ZS system (Malvern® Instrument). The exosomes were analyzed for surface markers using Western Blot, detecting CD63 and CD81, proteins characteristic of these structures. Through proteomics by mass spectrometry, the proteins present in the exosomes were identified. When analyzing the supernatant of neutrophils stimulated by Cr-LAAO, the presence of particles with exosome characteristics was observed, ranging in size from 8 to 70 nm. The expression of CD63 and CD81 markers in exosomes released by neutrophils stimulated by Cr-LAAO was confirmed by Western blot. In the proteomic analysis of exosomes, approximately 722 proteins were identified in all experimental groups, revealing their interactions and involvement in biological processes, molecular functions, and cellular components. These results provide an enhanced understanding of the role of Cr-LAAO in activating human neutrophils, resulting in the release of exosomes and facilitating intercellular communication. Additionally, they provide crucial information for potential therapeutic approaches in inflammatory and immunological disorders.

5
  • ANGÉLICA LORENA PEREIRA MENDES CARIOCA
  • .

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • ALEXSSANDRA RODRIGUES DE MEDONÇA FAVACHO
  • JANSEN FERNANDES MEDEIROS
  • THIAGO FERNANDES MARTINS
  • Data: 30 avr. 2024


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  • Ticks are obligatory ectoparasites of vertebrate animals, which could accidentally parasitize humans. In Brazil, only rickettsiae are known to cause illness to humans, however, there are lack of studies about other pathogens in this country, such as the bacteria Borrelia and Ehrlichia, especially in the Amazon region, where there are a great number of anthropophilic tick species. The Borrelia genus are spirochaete bacteria that infect mammals and birds worldwide, and some species can cause the human Lyme disease. There are recent records of Borrelia-infected ticks in Brazil, but the occurrence of any human borreliosis still lack of evidence, although cases of a Lyme-like have been reported. The relapsing fever is a zoonosis also provoked by Borrelia spirochaetes that are associated to argasid ticks from the Ornithodoros genus. Ehrlichia spp. is a genus of obligatory intracellular Gram-negative bacteria that infect phagocytes of humans and animals. Ehrlichia chaffeensis and Ehrlichia ewingii are etiological agents of, respectively, monocytic and granulocytic ehrlichiosis in North America. This study aimed to survey the incidence of Borrelia spp. and Ehrlichia spp. infecting freeliving and parasitic ticks in the region of the Porto Velho Natural Park (PVNP), Rondônia state. The collection of free-living and wild animals parasitic ticks were performed within trails in the forest area of the PVNP, whereas the ticks collections from domestic animals (dogs and horses) were performed in private properties in the surrounding areas of the Park. After collected, the ticks were identified and submitted to DNA extraction and nested-PCR to search for borrelial Flab gene DNA, and semi nested-PCR targeting ehrlichial dsb gene DNA. The PCR products were visualized in a 1.5% agarose gel. A total of 153 free-living ticks were collected and the most abundant species were Amblyomma scalpturatum, followed by Amblyomma sp., A. naponense and Amblyomma calcaratum. Regarding the method of collection, 70% of the ticks were collected by dragging, 18% by dragg-flagging and 12% by visual inspection. An infection rate of 4.6% of Ehrlichia canis was found in Rhipicephalus linnaei. The infection rates of E. canis were 2% in Amblyomma scalpturatum and 1% in Dermacentor nitens. The positive samples were confirmed to the ehrlichial species by DNA sequencing of dsb gene partial sequence. There were no Flab gene fragment detection in the tested ticks, suggesting that there were no borrelial infection in the ticks. Although Ehrlichia infection have been reported in horses, the present study reports E. canis in D. nitens parasitizing horses for the first time. This study is the first to report E. canis in A. scalpturatum. The results of this study indicate that non-native pathogens may be introduced to the wild tick fauna in Brazil, and could help in a better understanding of the tick-pathogen-host relationships in the Western Amazon Region.

6
  • GIL GUIBSON MOTA AMARAL
  • .

  • Leader : NAJLA BENEVIDES MATOS
  • MEMBRES DE LA BANQUE :
  • PATRÍCIA CARVALHO DE SEQUEIRA
  • LUANNA DA SILVA SOARES
  • NAJLA BENEVIDES MATOS
  • Data: 17 mai 2024
    Ata de defesa assinada:


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  • The coronavirus 2019 disease (COVID-19) pandemic has affected the child population directly and indirectly. Studies that prioritize these individuals are still scarce, as well as in the Northern Region of Brazil, which concentrates the highest death rates in children from COVID-19 in the country. The aim of this study was therefore to investigate the epidemiology of SARS-CoV-2 and its co-detection with other respiratory viruses in children in the state of Rondônia. This study involved 300 patients from the Cosme e Damião Children's Hospital, aged between 0.1 months and 12 years, from November 2021 to September 2022. The analyses were carried out using the RT-qPCR technique for 17 types of respiratory virus, including SARS-CoV-2, adenovirus; bocavirus; rhinovirus; HCoV-229E; HCoV-HKU1; HCoV-NL63; HCoV-OC43; metapneumovirus; respiratory syncytial virus A and B; parainfluenza 1,2,3; influenza A (H1N1, H3N2) and Influenza B. Specimens positive for SARS-CoV-2 were sequenced by next-generation sequencing (NGS) and the strains were classified using Nextclade. Our results showed that the detection rate for SARS-CoV-2 was 7.7% (23/300), with a higher prevalence for males with 82.6% (19/23), being statistically significant (0.0253*). Children under the age of 2 had higher detection rates for viral pathogens. The association between suspected or confirmed COVID-19 relatives in the same household and patient positivity was statistically significant (<0.0001*). The most frequent symptoms were fever with 60.9% (14/23), followed by coryza with 47.8% (11/23). The symptoms coryza (0.0498*) and headache (0.0151*) were statistically significant. 21.7% (5/23) of the positive cohort were sequenced, and the Omicron variant was associated with 80.0% (4/5) of the cases analyzed, all of which were associated with the AY.99.2 strain. The quantified viral load showed a median of 6.35 log10 copies/mL, with an average of 6 days of symptoms. The detection rate for other types of respiratory virus was 44.7% (134/300), of which rhinovirus was the pathogen with the highest detection rate, with 19.4% (26/134), followed by adenovirus with 15.7% (21/134). The codetection rate with SARS-CoV-2 was 30.4% (7/23), with higher findings for rhinovirus and influenza A/H3N2, with 28.6% (2/7) respectively. Therefore, this study has provided a better understanding of the behavior of SARS-CoV-2 and other viral pathogens co-circulating in the child population of the state of Rondônia. The data obtained in this study will add to future studies needed to resolve doubts that still exist about COVID-19 in the child population.

7
  • PRICILA GOMES DA SILVA
  • PURIFICATION OF A BOVINE LIVER CATHEPSIN D AND PARTIAL CHARACTERIZATION OF ITS INTERACTION WITH A PLA2 FROM Bothrops jararacussu.

  • Leader : LEONARDO DE AZEVEDO CALDERON
  • MEMBRES DE LA BANQUE :
  • LEONARDO DE AZEVEDO CALDERON
  • LUIS ANDRE MORAIS MARIÚBA
  • SHARON ROSE ARAGAO MACEDO OLIVEIRA
  • Data: 29 mai 2024
    Ata de defesa assinada:


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  • The enzyme Cathepsin D (CatD) and Phospholipase A2 (PLA2) play an important role in
    various pathophysiological conditions, being involved in processes ranging from
    neurodegenerative and inflammatory conditions to the life cycle of various parasites.
    Moraes et al. (2022) demonstrated the interaction of human CatD with BthTX-II, a PLA2
    from Bothrops jararacussu, forming a stable complex that modulates the activity of CatD,
    rendering it active at higher pH values. This phenomenon may be capable of assisting in
    the elucidation of some biochemical events related to CatD in the tumor
    microenvironment and Alzheimer's disease. Considering the high cost of obtaining
    human CatD for the continuity of studies, the present work proposes the adaptation of a
    new protocol for obtaining CatD from bovine liver (Bos indicus) and the partial evaluation
    of its interaction with a BthTX-II, aiming to enable future biophysical and structural
    studies. The methodology used to obtain the enzyme consisted of grinding 500g of
    bovine liver, followed by two solubilization/precipitation steps and subsequent
    fractionation on a Sepharose affinity column + Pepstatin A previously equilibrated with
    0.1M sodium acetate pH 5.0 and eluted in a step gradient of 0 to 100% sodium acetate
    pH 5.0 + 0.5M NaCl (buffer B) and 0.1M Tris-HCl pH 8.5 (buffer C) at a flow rate of
    1mL/min for 40 minutes. Subsequently, the sample was subjected to reverse-phase C18
    column chromatography (25 cm x 0.45 cm, Discovery) previously equilibrated with 0.1%
    trifluoroacetic acid and eluted under a gradient of 0 to 70% ACN 99.9% (v/v) and 0.1%
    TFA (v/v) at a flow rate of 1mL/min. The evaluation of relative mass, purity degree, and
    isoelectric point was observed on 12.5% SDS-PAGE and two-dimensional
    electrophoresis. The enzymatic complex was evaluated for its enzymatic activity on the
    substrate casein at different pH values, subjected to reading at 660 nm in a
    spectrophotometer. The predicted interaction between the proteins was observed in silico
    through molecular docking using the ClusPro tool and molecular dynamics simulations
    (MD) performed using the GROMACS program with the CHARMM36m force field. The
    bovine liver CatD exhibited a relative molecular mass of ~32 kDa, an approximate pI of
    5.5, and optimal activity on casein at pH 3 and temperature 50°C. The CatD/BthTX-II
    complex showed modulation in its catalytic activity, extending its activity on the casein
    substrate up to pH 6, with the optimal activity value at pH 5. In silico data highlight that
    the most predominant amino acid residues related to protein binding consist of
    hydrophobic residues. The complex showed little variation in its stability, suggesting
    significant structural resistance. Thus, the bovine liver CatD forms the same complex
    observed with its human analog and BthTX-II, enabling its use for subsequent structural
    studies.

8
  • MIRILENE MENDES MARTINS
  • Evaluation of the use of Toxic Sugar Bait Stations (TSB) in Aedes aegypti infestation on the José Ribeiro Filho Campus of the Federal University of Rondônia.

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • SÉRGIO LUIZ BESSA LUZ
  • ROSEMARY APARECIDA ROQUE
  • Data: 12 juil. 2024
    Ata de defesa assinada:


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  • Aedes aegypti is a vector of great importance to public health and the emergence of resistance to some insecticides demands complementary control methods, including toxic sugar baits (TSB), that have been used successfully in vector control. This tool aims to use sugar for the oral delivery of insecticides to mosquitoes. In this perspective, Ivermectin (IVM), an endectocide medication, has also been used as a toxic ingredient for TSB. Toxic sugar baits can be delivered using different devices, such as Bait Stations (BS). Although TSB and EI have the potential to be used together, studies on thos methodology apper to be incipient in Brazil. Therefore, the aim of this work was to assess the infestation of Ae. aegypti on the José Ribeiro Filho campus of the Federal University of Rondônia and the effect of using EIs with IVM TSB at some monitoring points. The study was conducted between October 2022 and June 2023, monitoring Ae. aegypti to evaluate the Egg Density Index (EDI) and the Ovitrap Positivity Index (OPI). For this purpose, ovitraps were installed at 17 points on the UNIR campus, monitored every 5 days. Based on this data, two monitoring points with high IDO and IPO were selected for the installation of 5 EI resting box types sprayed with TSB (sugar + aqueous solution with 500ppm IVM - intervention). From October 2022 to October 2023, the IPO at point 13 was more than 60%. Regarding the IDO, there was a reduction from 80 to 20 eggs between October 2022 and July 2023. During the intervention period with EIs, using shorter intervals (55 days) and longer intervals (120 days), there was a general reduction of 100 eggs at point 13 compared to the monitoring period. Point 7 presented the highest IPOs throughout the collections, reaching 100%. There was also a variation in IDO from 129 to 18 eggs. The use of EIs sprayed with IVM TSB at the intervention points reduced the infestation of Ae. aegypti.

9
  • JÉSSICA FERNANDA DOS SANTOS BARROSO
  • .

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • ALLAN KARDEC RIBEIRO GALARDO
  • FRANCISCO AUGUSTO DA SILVA FERREIRA
  • Data: 2 sept. 2024
    Ata de defesa assinada:


  • Afficher le Résumé
  • Biolarvicides are agents that stand out worldwide in the biological control of mosquitoes of medical importance, reinforcing the initiative of harmless control and thus avoiding the accelerated use of chemical means, which minimizes problems related to resistance in various mosquito species. Given this versatility, we evaluated the effectiveness of two products, Vectobac-WG® and Vectomax-FG®, against the larvae of two species of Mansoniini in the laboratory. First-stage larvae (L1) of Ma. humeralis and Ma. titillans were obtained from field females and L1 larvae of Aedes aegypti from the laboratory were used as a comparison parameter for bioassays, which followed the World Health Organization (WHO) protocol (with adaptations), in an environment with controlled temperature (T) and relative humidity (RH) (T 25 - 27ºC / RH -70 - 80%). Different concentrations of Vectobac-WG 3. 000 UTI/mg (0.00025ppm, 0.0005ppm, 0.001ppm, 0.002ppm, 0.004ppm and 0.008ppm), and Vectomax-FG 50 UTI/mg (0.00031ppm, 0.00062ppm, 0.00125ppm, 0.0025ppm, 0.005ppm and 0.01ppm) were tested as larvicides using 50 L1 larvae in triplicates, with four repetitions at different times. Larval mortality was monitored for up to 48 hours. The persistence of the same products was tested in two lighting conditions (light and dark) for 35 days. The dose-effect and persistence of the products on the larvae were analyzed using the Kruskal-Wallis test (non-parametric ANOVA), and Dunn's test was used for multiple comparisons at a 5% significance level. To obtain the lethal concentrations (CL50 and CL90) after 24 and 48 hours, Probit analysis was carried out (concentration x mortality). Vectobac-WG caused an average mortality of 61.1% for Ma. humeralis, 70.8% for Ma. titillans and 37.7% for Ae. aegypti. Treatment with Vectomax-FG resulted in mortality of 50.1% for Ma. humeralis, 53.7% for Ma. titillans and 51.1% for Ae. aegypti. The estimated lethal concentrations (LC) of Vectobac-WG for Ma. humeralis and Ma. titillans were LC50 from 0.0004ppm to 0.0008ppm and LC90 from 0.0019ppm to 0.0029ppm, respectively. The CLs estimated for Vectomax-FG for Ma. humeralis and Ma. titillans were higher, i.e., CL50 0.0016ppm to 0.0018 ppm and CL90 0.0051ppm to 0.0061ppm, respectively. After an evaluation of 5 weeks from the start of application in the laboratory, the product Vectomax-FG caused mortality of > 66% up to the 3rd week for the two lighting conditions evaluated and Vectobac-Wg caused larval mortality of more than 50% under the use of direct light up to the 3rd week, this product showed mortality of 43% up to the 2nd week in the dark. In view of the results, we concluded that the larvae of Ma. humeralis and Ma. titillans were susceptible to the products Vectobac-WG and Vectomax-FG. The mortality of the larvae depended on the concentration of the product used, the type of bacilli and the species of mosquito used. The products persisted for 21 days, with mortality ranging from 100% to 58%. From the second week onwards, there was a noticeable difference between the lighting conditions.

10
  • KEITHY WENNY PLASTER LIMA
  • .

  • Leader : DHELIO BATISTA PEREIRA
  • MEMBRES DE LA BANQUE :
  • ANNA CAROLINE CAMPOS AGUIAR
  • DHELIO BATISTA PEREIRA
  • SIMONE DA SILVA SANTOS
  • Data: 29 oct. 2024
    Ata de defesa assinada:


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  • INTRODUÇÃO: Malaria is an infectious disease caused by the parasite of the genus
    Plasmodium. In Brazil, the species that infect humans are P. vivax, P. falciparum, and
    P. malariae, with Plasmodium falciparum being the most lethal species. Despite
    efforts to control the disease, 128,076 cases were recorded in the country in 2022.
    Diagnostic techniques include routine microscopy, rapid diagnostic tests (RDTs) for
    the detection of antigens from pfhrp2/3 genes, and Polymerase Chain Reaction
    (PCR). Discrepancies between RDT and other techniques point to genetic variations
    in Plasmodium, which can affect the diagnosis, control, and monitoring of malaria.
    Despite the World Health Organization's recommendation for monitoring deletions in
    pfhrp2/3 genes, such data are scarce in Brazil. OBJETIVO: Analyze the prevalence
    of malaria through microscopy, immunochromatography, and molecular approaches,
    including the study of genetic variations in P. falciparum. METODOLOGIA: This
    study is approved by the CEP/CONEP system. Socio-epidemiological data and
    venous blood samples from 995 patients were used for population characterization
    and Plasmodium detection through thick blood smear microscopy, RDTs, and
    molecular tests by qPCR. Additionally, for genetic diversity analyses, all positive
    cases for P. falciparum underwent amplification of pfhrp2 and pfhrp3 genes followed
    by Sanger sequencing. RESULTS AND CONCLUSION: The positive diagnosis for
    malaria by microscopy was 40% of participants (394/995), while in RDTs it was
    observed to be 41% (405/995), and by qPCR, it was 46% (457/995). Through qPCR,
    it was also possible to detect the presence of one sample positive for P. malariae and
    two samples with co-infection of P. vivax and P. falciparum. The majority prevalence
    of Plasmodium vivax was observed in over 90% of cases. Additionally, 18% (82/457)
    showed discordance in the identification of Plasmodium species between microscopy
    and qPCR techniques, and 12% (57/457) were discordant between RDTs and qPCR.
    Furthermore, evidence of deletions in pfhrp2 and pfhrp3 was identified for 8 cases
    positive by microscopy for Plasmodium falciparum and negative by RDTs, as well as
    4 cases positive by qPCR and negative by RDTs. The presence of deletions
    observed in this study highlights the genetic variability of Plasmodium falciparum in
    the population, with a high frequency of deletion in pfhrp3 (94%; 48/51) and a
    significant frequency for pfhrp2 (18%; 9/51), unlike what has been reported in
    previous studies. These findings are further supported by the presence of significant
    amino acid substitutions and/or deletions/insertions not previously described in the
    literature, with potential clinical implications for diagnosis and treatment. Thus, the
    data from this study emphasize the importance of epidemiological surveillance of
    malaria cases in the region.

11
  • CLAUDIA CHRISTIAN BEZERRA DE SOUZA
  • .

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • JOELMA SOARES DA SILVA
  • ALEXANDRE DE ALMEIDA E SILVA
  • ROSEMARY APARECIDA ROQUE
  • Data: 30 oct. 2024
    Ata de defesa assinada:


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  • The mosquito Aedes aegypti is an arthropod vector of viruses such as Dengue,
    Zika, Chikungunya, and urban Yellow Fever. Only Dengue and Yellow Fever
    have vaccines as preventive treatments, with vector control still being a method
    for suppressing arboviral diseases and preventing new outbreaks. Therefore,
    discovering substances and their applicability for vector control is an ongoing
    pursuit. Given this context, the objective of this study was to evaluate the
    insecticidal effects of essential oil and vegetable oil on different life stages of Ae.
    aegypti. Essential oil from Morinda citrifolia fruit (OE noni) and vegetable oil from
    Carapa guianensis seed (OV andiroba) were used to assess ovicidal (20
    eggs/treatment), larvicidal (10 L3 larvae/treatment), pupicidal (10
    pupae/treatment), and adulticidal activity through the ingestion of sugar baits (20
    females/treatment). The protocol adapted from the World Health Organization
    was used in tests with concentrations ranging from 1000, 750, 500, 250, 125, 50,
    25, 10, and 5 ppm, with distilled water and 1% ethanol controls, and three
    replicates and three repetitions with different generations. The tests were
    observed for 24 to 72 hours. No ovicidal effect was observed for either oil at the
    tested concentrations, except for the OE noni higher concentration. The larvicidal
    activity of OE noni resulted in LC50 (24 h) 90.1 ppm and LC90 (24 h) 146.1 ppm,
    causing 100% mortality at concentrations from 250 to 150 ppm in the first 24
    hours of the bioassay. OV andiroba had LC50 (24 h) 646.7 ppm and LC90 (24 h)
    3048.3 ppm, causing 66.67% mortality at 250 ppm and 58.33% at 400 ppm after
    48 hours of observation. The pupicidal activity of OE noni resulted in LC50 387.6
    ppm and LC90 588.3 ppm, causing 82.22% mortality at 500 ppm and 64.44% at
    450 ppm in the first 24 hours of the bioassay. OV andiroba had LC50 (24 h)
    1460.02 ppm and LC90 (24 h) 2701.7 ppm, causing 98.89% mortality at 3000
    ppm and 2500 ppm in the first 24 hours. No adulticidal activity was observed from
    the ingestion of either oil (OE noni and OV andiroba) at the tested concentrations,
    despite high ingestion. It is concluded that both oils exhibited insecticidal activity
    against the larval and pupal stages of Ae. aegypti. Additionally, the consumption
    of sugar baits containing both oils did not result in adult mortality at the tested
    concentrations, regardless of the high level of engorgement.

12
  • AMÉLIA MACARLE SILVA DE SOUSA
  • .

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • FRANCISCO AUGUSTO DA SILVA FERREIRA
  • LUIZ GUILHERME SOARES DA ROCHA BAUZER
  • Data: 5 nov. 2024
    Ata de defesa assinada:


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  • The genus Mansonia Blanchard, 1901 comprises 25 species classified within the
    tribe Mansoniini, divided into two subgenera: Mansonia (Mansonia) (with 15
    species) and Mansonia (Mansonioides) (with 10 species). Only Mansonia
    (Mansonia) occurs in the Neotropical region. During the oviposition process, the
    eggs are deposited on the underside of the leaves of the plants used as
    substrates. Some studies have highlighted the association of Mansonia species
    with aquatic macrophytes Eichhornia crassipes and Pistia stratiotes in Asia and
    North America. However, laboratory studies on the oviposition preference of
    Mansonia in Brazil have not been found. Therefore, this study aimed to analyze
    the oviposition preference of Mansonia humeralis in aquatic macrophytes under
    two experimental conditions in the laboratory. For this, female Mansonia
    humeralis were collected by human-protected bait and placed in plastic cages,
    being fed human blood for 15 minutes in the field. Three days after the blood
    meal, the females were identified and placed inside BugDorm cages/traps (L 32.5
    x W 32.5 x H 32.5 cm) with rectangular plastic basins containing 1.8 liters of
    filtered water for five days, containing the specific substrates of the treatments,
    divided into two distinct groups. The Isolated Substrates group (IS): (i) E.
    crassipes plant; (ii) P. stratiotes plant; (iii) Salvinia spp., and (iv) abiotic substrate
    expanded polystyrene (EPS). The Combined Substrates group (CS) consisted of
    (v) all plants + EPS (MIX). After this period, the oviposition substrates were
    inspected for posture quantification and egg and larval counting. A total of 886
    females were used, and 66 oviposition’s (7.46%) were recorded. Among the 66
    recorded oviposition’s, 40 (60.6%) were in the IS group, and 26 (39.4%) in the
    CS group. Regardless of the experimental group, no females oviposited on E.
    crassipes. In the IS group, of the 40 recorded oviposition’s, 50% of the females
    oviposited on Salvinia sp., 35% on P. stratiotes, and only 15% on EPS,
    suggesting a preference for these plants compared to the inert substrate (EPS).
    In the SC group, of the 26 recorded oviposition’s, 42% were on Salvinia sp., 34.6%
    on P. stratiotes, and 23% on EPS, with no differences in the frequency of
    oviposition among these substrates. The results suggest that Mansonia
    humeralis does not oviposit on E. crassipes but oviposits more frequently on the
    other plants compared to EPS under the experimental laboratory conditions used.
    A total of 6,054 eggs were obtained without induction, showing no significant
    difference between the plants Salvinia (92) and Pistia (88) and the abiotic
    substrate (94). A total of 2,568 larvae were obtained, with a hatching rate of 42%.
    There was a significant difference between the number of larvae hatched on EPS
    (60) compared to the plants, but no difference between Salvinia (45) and Pistia
    (27). Regarding larval preference, a significant difference was observed in larval
    attachment to Pistia (88) compared to the other substrates, Eichhornia (45) and
    Salvinia (23).

13
  • HILLQUIAS MONTEIRO MOREIRA
  • .

  • Leader : DHELIO BATISTA PEREIRA
  • MEMBRES DE LA BANQUE :
  • DHELIO BATISTA PEREIRA
  • GENIMAR REBOUÇAS JULIÃO
  • MONICA BARCELLOS ARRUDA
  • Data: 12 déc. 2024
    Ata de defesa assinada:


  • Afficher le Résumé
  • The Oropouche virus - OROV, is characterized as a re-emerging arbovirus of great concern to public health due to its capacity for genetic rearrangement, and since its discovery has been responsible for several outbreaks of acute fever identified in Central and South American countries, with at least 500,000 reported cases. The western Amazon region is already notorious for outbreaks of acute febrile illnesses, for which the lack of specific diagnoses for different pathogens makes patient management difficult. The OROV was already recorded in the region in the 1990s, and this is the first study since that record to detect individuals with acute febrile illness using a screening test to exclude Zika, dengue and chikungunya, confirming by sequencing the circulation of the Oropouche virus in the state of Rondonia and the border. Reports of the incidence of this virus are intrinsically favored by environmental and climatic conditions, which can favor the increase and distribution of the vector population to areas of human traffic. In addition, there is a problem related to the lack of distribution of the specific diagnosis established in routine screening for arboviruses in Brazil. Thus, through molecular techniques of RT-qPCR (Reverse Transcription quantitative Polymerase Chain Reaction) used as a primary exclusion methodology for Zika, dengue and Chikungunya, and evaluating profiles of OROV co-infections with other arboviruses. Sanger sequencing confirmed the circulation of the Oropouche virus in the state of Rondonia and the border. 20.99% (421/2006) positive OROV cases were identified, with detections of 1.43% (6/421) for co-infections with dengue (serotypes 1 and 2) circulating in border locations in western Amazonia, among serum samples, with 95.81% (366/382) of the cohort characterized as infected individuals with reported symptoms, mainly fever, headache, myalgia, and back pain. Among the positive samples, it was possible to obtain a total of 3.40% (13/382) of samples for analysis of the S and M segments of Oropouche, which showed similarities with Brazilian sequences. It was thus possible to verify the circulation of OROV in Rondonia and border areas, strengthening genomic surveillance of emerging and re-emerging viruses.

Thèses
1
  • NORTON RUBENS DIUNIOR LUCAS PEJARA ROSSI
  • Susceptibility of Leishmania (Leishmania) amazonensis to antimalarials: An alternative for the in vivo study of drug repositioning 2024. Thesis (Doctorate in Experimental Biology) – Postgraduate Program in Experimental Biology, Federal University of Rondônia, Rondônia, 2024.

  • Leader : CAROLINA BIONI GARCIA TELES
  • MEMBRES DE LA BANQUE :
  • ALEJANDRO FERRAZ DO PRADO
  • CAROLINA BIONI GARCIA TELES
  • DANIELLE LAZARIN BIDÓIA
  • KARINE MODOLON ZEPON
  • NIDIANE DANTAS REIS PRADO
  • Data: 26 avr. 2024
    Ata de defesa assinada:


  • Afficher le Résumé
  • Leishmaniases are endemic parasitic diseases of concern to Brazilian public health. The state of Rondônia is an area where the disease is transmitted, with an average incidence of 721 cases between the years 2018 and 2022. The limitations of treatments for this disease, the increasing resistance, and the therapeutic failure associated with some species are important aspects indicating the urgency of new therapeutic drugs. Repurposing drugs with confirmed action against other protozoa can accelerate the discovery of alternative therapies for leishmaniasis and expand the market for products whose toxicological description has already been submitted to drug regulatory authorities. Recent in vitro tests against Leishmania promastigotes and amastigotes, conducted by our group of researchers, have shown leishmanicidal action of some antimalarials, which led to the design of this study. The aim of this study is to evaluate the in vivo susceptibility profile of Leishmania (Leishmania) amazonensis to antimalarials alone or in combination with the reference drug amphotericin B. By infecting Balb/c mice with the parasite, it was possible to assess the parasitic load of the paw lesion, obtaining the effective dose for 50% parasite death (ED50) of amphotericin B (0.63 mg/kg), artesunate (3.13 mg/kg), and chloroquine (27.29 mg/kg). With these data, combinations of antimalarials with amphotericin B were performed, yielding contrasting results. While the combination with artesunate resulted in increased parasitemia, the combination with chloroquine led to a decrease. The latter, although not resulting in complete cure, was statistically equivalent to the naive group. In this study, the dosage of biochemical metabolites and serum cytokines was quantified using commercial kits. Both antimalarials showed no toxicity at the ED50 dosage. As a result of quantifying these cytokines, it was observed that artesunate elicited an immune response similar to the untreated infection group, whereas chloroquine, despite exhibiting anti-inflammatory activity, was effective in increasing IFN-γ production. The prospects of this study are to expand the alternatives of chemotherapeutic formulations and foresee the rational use of drugs to overcome existing limitations.

2023
Thèses
1
  • CLEICIAINARA BAGIO LOVO
  • Molecular epidemiology of Candida species isolated from patients in the region of Porto Velho, RO, Brazil.

  • Leader : CHRISTIAN COLLINS KUEHN
  • MEMBRES DE LA BANQUE :
  • CHRISTIAN COLLINS KUEHN
  • ORMEZINDA CELESTE CRISTO FERNANDES
  • ANDRELISSE ARRUDA
  • Data: 14 mars 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • Candida spp. they colonize the human organism in a commensal way, only, depending
    on the states of the host, these microorganisms can to comport as opportunistic agents
    and cause from superficial infections to systemic infections. These infections result in
    prolonged hospitalizations, increased hospital costs, and high rates of morbidity and
    mortality. Despite this, when it comes to the northern region of Brazil, studies on
    candidiasis are scarce, and in Rondônia, they are non-existent. Therefore, the present
    study aimed to carry out the molecular characterization of clinical isolates of Candida
    spp. obtained from patients in the Porto Velho/RO region, as well as to phenotypically
    determine virulence factors and antifungal susceptibility. For this, the isolates were
    obtained from clinical specimens of patients attended at the Laboratory of Medical
    Mycology of the Centro de Pesquisa em Medicina Tropical de Rondônia (CEPEM/RO),
    which were first identified through the CHROMagar Candida medium. Molecular
    characterization of the species was performed through PCR of the ITS region of fungal
    rDNA coupled to genetic sequencing. The disk diffusion method was used following
    the recommendations of the M44-P protocol to determine antifungal susceptibility to
    nystatin, amphotericin B, fluconazole, itraconazole and miconazole. To determine the
    hemolysin activity, the sheep blood agar assay was used and, to determine the
    phospholipase activity, the egg yolk agar method was used. The present study
    evidenced the presence of five species of Candida as causing infections in patients in
    the Porto Velho/RO region, of which C. albicans 22/31 (71%) was the most frequent,
    followed by C. tropicalis with 6/31 (19,4%), C. parapsilosis with 1/31 (3,2%),
    Cyberlindnera jadinii with 1/31 (3,2%) and C. duobushaemulonii with 1/31 (3,2%).
    Resistance to fluconazole was observed in 26/30 (86,7%) isolates and to itraconazole
    in 24/30 (80%) isolates, mainly in species of C. albicans, C. tropicalis and
    Cyberlindnera jadinii, evidencing a reduction in the sensitivity of Candida spp. to first
    option triazole antifungals. Besides, the present study demonstrated that 30/30 (100%)
    of Candida isolates were hemolysin producers and that only C. albicans 9/22 (40,9%)
    and Cyberlindnera jadinii 1/1 (100%) were phospholipase producers. These results
    inedited provide important information for the management of infections in relation to
    strategies of the treatment, control and prevention of the cases of candidiasis
    diagnosed in the region.

2
  • YODA JANAINA IKENOHUCHI
  • .

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • FABIO HENRIQUE KWASNIEWSKI
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • SORAYA DOS SANTOS PEREIRA
  • Data: 1 juin 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • Lectins are a large group of proteins found in all snake venoms. BjcuL, a C-type lectin, isolated from Bothrops jararacussu snake venom, does not have a cytotoxic effect on human peripheral blood mononuclear cells (PBMCs), but demonstrates an immunomodulatory role, inducing the production of pro- and anti-inflammatory cytokines (IL -2, IL-10, IFN-γ, IL-6, TNF-α, and IL-17), in addition to stimulating T cells to produce reactive oxygen species (ROS), which may play a role in the observed acute inflammatory reaction in victims of envenoming. ROS production can trigger the activation of the NLRP3 inflammasome complex. Inflammasomes are essential in innate immunity cells, detect various endogenous or exogenous, sterile or infectious stimuli, and stimulate cellular responses and effector mechanisms. The NLRP3 inflammasome is an important target, as the lectin is responsible for the activation of leukocytes that stimulates the release of inflammatory mediators resulting in dynamic cellular responses to restore homeostasis in snakebite victims. Thus, this study aimed to investigate the action of BjcuL isolated from Bothrops jararacussu snake venom on activating the NLRP3 inflammasome complex in human PBMCs. PBMCs were isolated by density gradient and incubated with BjcuL at different periods and concentrations. Activation of the inflammasome complex was evaluated through gene and protein expression of ASC, CASPASE-1, and NLRP3 by RTq-PCR, Western blot, and immunofluorescence, as well as the participation of Toll-like receptor 4 (TLR4) and mitochondrial ROS (mROS) in the production of IL-1β, a product resulting from the activation of the NLRP3 inflammasome. The data showed that BjcuL interacts with TLR4 and induces cytokine release via NF-κB signaling. It was demonstrated by gene and protein expression assays, that BjcuL activates the NLRP3 inflammasome, and pharmacological modulation with LPS-RS, TLR4 antagonist; LPS-SM, TLR4 agonist; MCC950, a specific NLRP3 inhibitor; and rotenone, an mROS inhibitor, confirmed the activation of the inflammasome through the release of its product IL-1β, and also the participation of TLR4 and mROS. It was verified that the effects of BjcuL in the regulation and activation of the NLRP3 inflammasome complex via activation of TLR4 with the participation of mROS can be a determinant for the development of the local inflammatory effects observed in victims of envenoming.

3
  • EDIVÁ BASILIO DA SILVA FILHO
  • .

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • ANDRELISSE ARRUDA
  • MICHELE OLIVEIRA DOS SANTOS
  • Data: 22 juin 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • COVID-19 is the disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2) that had the first confirmed case in November 2019 and in March 2020 it was officially considered a pandemic. With this rapid spread, rapid diagnosis is a key part of actions to combat the disease. SARS-CoV-2 is expected to become a regular seasonal epidemic agent in the calendar of respiratory viruses. Thus, even outside the pandemic period, referral hospitals and health centers will receive patients suspected of COVID-19, requiring sensitive, accurate and adequate tests for low demand. Point of care (POC) tests can bring advantages such as savings in materials and supplies and a reduction in diagnosis time. The objective of this work is to standardize a POC molecular test to aid in the diagnosis of COVID-19 using a portable qPCR device called Q3-Plus, verifying the performance of this equipment in comparison to bench equipment used as the gold standard for diagnosis. And finally, compare the results obtained using a commercial RT-qPCR protocol and an adapted one. The study population consisted of 50 patients from the state of Rondônia with samples of nasopharyngeal secretion collected between March and April 2020 for SARS-CoV-2 research, processed using the RT-qPCR technique using the ABI 7500 fast equipment, com its results released by Lacen Rondônia through the Gal System. The first stage of the tests consisted in the standardization of the qPCR reaction in the Q3 plus equipment using a multiplex that uses the N1 region (CDC) as a viral target and the RNP as an endogenous target. In this step, a plasmid was used. After that, the 50 RNAs were used in the sensitivity and specificity, repeatability and reproducibility tests. Using a 6-point plasmid dilution curve as a sample, the Q3 plus was able to detect up to 1.25 copies of the viral target in the reaction, exhibiting a slope of -2.98 and an efficiency of 116%, in addition to 100% of agreement between the results of reproducibility and repeatability tests. The Point of care molecular test has been shown to be sensitive and specific for the SARS-CoV-2 virus, as it has shown agreement with the results obtained with other equipment or kits and is still reproducible for more than one year operator with 100% agreement on the results.

4
  • ANA MAISA PASSOS DA SILVA
  • .

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • RAQUEL DA HORA BARBOSA
  • MICHELLE DE OLIVEIRA E SILVA
  • Data: 23 juin 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • SARS-CoV-2 has been characterized as a virus that has generated great public health commotion due to its scenario. For the different clinical manifestations, components of the immune system constitute a huge population of proteins, associating themselves to a large line of defense related to innate and adaptive responses in viral infections. As originators, the performance and the genetic role in the host immune response delimit specific points of investigation that will demonstrate the association of a variety of potential genes of immunogenic behavior, as well as biomarkers that would be linked to the severity of clinical pictures. Thus, this research aimed to identify potential biomarkers in the worsening of the disease caused by SARS-CoV-2 in patients in Western Amazon. For this purpose, biological materials were collected from 223 individuals diagnosed positive for SARS-CoV-2 obtained by molecular biology and/or antigen testing, and from 20 individuals as a control population with negative diagnosis for SARS-CoV-2. Real-time PCR techniques were used for human genotyping of the targets rs2070788, rs4702, rs76635825, rs540856718, rs35803318, rs12979860 and rs16899066, as well as gene expression of the markers ACE2, HLA-A, HLA-B, IFN 3/2, IL-6 and TMPRSS2. For the analysis of genetic results, the allele and genotype frequencies were assigned along with the Hardy Weinberg Equilibrium. The other results were tabulated and calculated according to Fisher's exact test. In the study it was possible to verify that rs12979860 is already a highly adapted and disposed polymorphism among the population, as well as rs540856718 which had 100% identification of the CC genotype among all those analyzed. At the same time, the other SNPs were found to have genetic imbalance for this population, especially rs2070788 with the G allele substitution present in a large portion of mapped people. The results regarding gene expression showed quite high levels among the moderate and severe groups. The ACE2 gene showed no correlation with the disease. In the control population, the levels were commonly stable. TMPRSS2 and IL-6 performed better in gene expression analysis than the others. Thus, it was seen that there is possibly an association regarding the role of rs2070788 in SARS-CoV-2 infection, just that the polymorphism had p<0.05, being significant in the comparison of the clinical outcomes analyzed. As well as the correlation of overexpression of the TMPRSS2 gene among the more aggravated groups, in addition to the relationship of the immune response of IL-6 and the IL-6 gene verified.

5
  • GABRIELLA SGORLON OLIVEIRA
  • .

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • MATHEUS FILGUEIRA BEZERRA
  • ZORAIDA DEL CARMEN FERNADEZ
  • Data: 3 juil. 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • The COVID-19 pandemic showed the importance of genomic surveillance for rapid responses to
    decision-making in the control of emerging and re-emerging diseases. SARS-CoV-2 had an
    increase in mutations and infection cases during the second wave of infections that started in
    December 2020 in Manaus, observing an increase of subvariants in circulation in subsequent
    periods. Among the most critical features of the virus is the ability to evade the adaptive immune
    response mounted against SARS-CoV-2. Thus, even with the increase in vaccination rates, there is
    a great and justifiable need to continue surveillance for SARS-CoV-2 and subsequent lineages that
    may emerge. Thus, the objective of this study was to analyze the epidemiological data and the
    genetic diversity of SARS-CoV-2 in the state of Rondônia. Samples collected from different units
    in the state were screened by qualitative diagnostic amplification ct<25 for SARS-CoV-2 at
    LACEN/RO. The epidemiological and clinical data of the individuals were collected through
    electronic medical records, subsequently the samples were extracted using a commercial kit, then
    evaluated for viral load and sequenced using the COVIDSEQ Kit (Illumina). Analysis of sequence
    quality and mutations were performed by Pangolin and Nextclade, and at the end, phylogeny was
    performed using the maximum likelihood method. The results showed the circulation of 5 lineages
    in Rondônia between 2021 and 2022, where Gama, Delta and Omicron were the most prevalent
    variants, and to a lesser extent, the Zeta and Mu clades. Regarding sex, it was found that there was
    a prevalence of female sex and the individuals had a median age of 40 years. The most commonly
    reported symptoms were sore throat, cough, and fever, with no statistical differences in relation to
    the variants present in the study. The viral load was measured, presenting a median of 7.35 log10
    copies/ml. Among the variants, the VOC Omicron had the highest number of subvariants and
    mutations in the S gene. Moreover, the gamma variant had the highest prevalence of mutations
    when the ORFab, S, E, and N genes were evaluated. There was a higher number of unvaccinated
    individuals in this cohort, where statistical analyses showed that vaccination was a protective factor
    for hospitalizations. ML phylogeny confirmed the clades circulating in the state of Rondônia. In
    conclusion, the results showed the clinical epidemiological profile compiled with the data
    generated by genomic surveillance of SARS-CoV-2 infections, tracing a profile of how the
    infections were in the state of Rondônia in the years of the study. This work was an important
    initiative for genomic surveillance in the state of Rondônia, which helped the state government
    make decisions in the face of SARS-CoV-2 epidemic waves.

6
  • RENATA BISPO SANTOS
  • .

  • Leader : GABRIEL EDUARDO MELIM FERREIRA
  • MEMBRES DE LA BANQUE :
  • GABRIEL EDUARDO MELIM FERREIRA
  • PATRÍCIA FLÁVIA QUARESMA
  • OTACILIO DA CRUZ MOREIRA
  • Data: 28 juil. 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • Tegumentary leishmaniasis (TL) is a disease with a wide geographic distribution, occurring in four continents: Americas, Asia, Europe and Africa. In Brazil, eight Leishmania species that cause TL were identified, all occurring in the North region. Leishmania braziliensis and Leishmania. guyanensis are the most frequent species in cases of TL and some strains have a viral endosymbiont, LRV1, which has been associated with the clinical evolution of TL from the cutaneous to the mucosal form. The laboratory diagnosis is made through direct parasitological, immunological and molecular techniques such as PCR and its variations. In view of the molecular techniques that have been used in the diagnosis of TL, qPCR is a method that optimizes the diagnosis, as it combines greater sensitivity and specificity with efficient and quantitative detection. Therefore, this study aimed to evaluate the use of qPCR approaches to quantify the parasite and viral load in the routine diagnosis of TL, in patients treated at the Centro de Medicina Tropical de Rondônia (CEMETRON), using samples of lesions, blood and healthy mucosa. Only patients who had a skin lesion with suspected TL were included in this study. The samples were subjected to genetic material extraction, reverse transcription (for LRV1 RNA) followed by qPCR for Leishmania detection and quantification with the 18S rDNA target and LRV1 ORF1 region. Of the 100 samples included in the study, 62 showed a positive result in at least one of the tests, however qPCR showed high sensitivity in relation to the other methods, which demonstrates that the method is robust and reliable to be used in the routine diagnosis of TL. Detection of LRV1 was possible in 26 samples from skin lesions, 4 from blood and 11 from healthy mucosa. With the methodology used, it will be possible to evaluate the dissemination of the parasite as well as a more precise clinical follow-up.

7
  • TALIA IASMIN PEREIRA DA SILVA
  • .

  • Leader : FERNANDO BERTON ZANCHI
  • MEMBRES DE LA BANQUE :
  • JULIANE CORRÊA GLÓRIA
  • ANNA CAROLINE CAMPOS AGUIAR
  • FERNANDO BERTON ZANCHI
  • Data: 5 oct. 2023


  • Afficher le Résumé
  • Studies carried out in vivo and in vitro demonstrated that the P53 protein and the cytokine IFN-γ may be involved in protective mechanisms against Plasmodium infection. The objective of this study was to analyze the expression level of the TP53 and IFNG genes in infection caused by P. vivax in different parasitemias in patients treated at the Tropical Medicine Research Center – CEPEM. A total of 52 samples were collected, which were classified into 4 groups with different parasitemias: +/- (half a cross), + (one cross), ++ (two crosses) and +++ (three crosses). Extraction and purification of total RNA from whole blood and cDNA synthesis were performed. The optimal primer concentration and cDNA efficiency were determined to standardize the real-time PCR technique. To evaluate the variation in expression, the comparative Ct methodology was used, given by the search ΔCT: Ct gene of interest – Ct of the control gene. Ct values of the TP53 and IFNG genes were obtained, using the GAPDH gene as an endogenous control.

    Note a reduction in TP53 gene expression in patients with high parasitemia +++ (three crosses) compared to those with lower parasitemia. However, no statistically significant difference was found when comparing the other groups to each other. Expression of the IFNG gene did not vary significantly with different levels of parasitemia. The results support studies that indicate that the parasite can suppress P53 levels in the host to continue its life cycle.

8
  • WELINGTON DA SILVA PAULA DO NASCIMENTO
  • .

  • Leader : CAROLINA BIONI GARCIA TELES
  • MEMBRES DE LA BANQUE :
  • CAROLINA BIONI GARCIA TELES
  • PAULO RENATO RIVAS TOTINO
  • SARAH EL CHAMY MALUF
  • Data: 20 oct. 2023


  • Afficher le Résumé
  • Malaria is a febrile disease caused by the protozoan Plasmodium spp., responsible for high rates of morbidity and mortality worldwide. The development of new antimalarial compounds is crucial to address the growing challenge of drug resistance. Based on this premise, triazole compounds, which feature two linked nitrogen-containing heterocyclic rings, known as bi-triazoles, are molecules with rapid production and various described activities in the literature. Recent antimalarial studies have demonstrated the significant potential of this chemical class. In this context, this study aimed to assess the antimalarial activity of the bi-triazole compound (4-(phenoxy methyl)-1-(5-trifluoromethyl)-4H-1,2,4-triazol-3-yl)1H-), in both asexual and sexual forms of circulating Plasmodium falciparum W2 and Plasmodium vivax. The tests began with the W2 strain of P. falciparum, assessing its toxicity in HepG2 and VERO cell lines and its toxicity to human erythrocytes. Additionally, the inhibitory potential in circulating isolates of P. falciparum and P. vivax was evaluated, the molecule's selectivity index (SI) in relation to the tested cells was determined, and the molecule's inhibitory potential in inhibiting P. vivax ookinete formation was assessed. The inhibitory concentration of 8RJ on W2 P. falciparum parasites was determined by the SYBR Green method, and cell cytotoxicity was observed through the MTT method. Ex vivo assays with Plasmodium spp. isolates obtained from patients were monitored by optical microscopy for up to 60 hours of incubation. SI results were calculated from the ratio of CC50 (50% cytotoxic concentration) and IC50 (50% inhibitory concentration). Ookinete formation inhibition was revealed by optical microscopy after 24 hours of incubation with ookinete medium. In silico analysis of the compound was performed using Molinspiration and Osiris software. The obtained results showed that the compound 8RJ had an IC50 value of 5.2 μM ± 2.5 considering the asexual forms of the W2 strain, without displaying toxicity for the tested hepatic and renal cells (CC50 ≥ 500 μM) in vitro. Furthermore, 8RJ showed no hemolytic effect. The compound proved to be selective against the protozoan (SI ≥ 10). The compound's action velocity data indicated its ability to inhibit protozoan growth within the first 8 hours. Inhibition results of circulating strains of P. vivax and P. falciparum showed a median IC50 of 5.2 μM and 6.35 μM, respectively, corroborating with those obtained in the W2 strain. However, it was not able to inhibit the growth of sexual forms of the parasite, inhibiting only 15.7% of parasites at 10 μM. In summary, the preliminary results of this study provided promising evidence of the antimalarial potential of the bi-triazole compound 8RJ. The compound exhibited activity against the asexual forms of the parasite in in vitro assays without cytotoxicity for the tested cells. Additionally, it showed inhibitory activity in the early hours of the parasitic cycle and was effective against circulating isolates. However, it did not demonstrate inhibitory activity against P. vivax ookinetes. In silico analysis indicated that the compound possibly lacks toxicity and will have good bioavailability. The obtained results are important for demonstrating the antimalarial potential of the bi-triazole group, enriching this study's target with new information.

9
  • THIAGO REIXACH PIRES DE SOUZA
  • .

  • Leader : NAJLA BENEVIDES MATOS
  • MEMBRES DE LA BANQUE :
  • NAJLA BENEVIDES MATOS
  • CLARICE MAIA CARVALHO
  • DEBORAH ANTUNES DOS SANTOS
  • Data: 8 déc. 2023
    Ata de defesa assinada:


  • Afficher le Résumé
  • Antibiotics, whether natural or synthetic, are the main tools in combating bacterial infections. However, the inappropriate and extensive use of antibiotics has favored the emergence of strains of bacteria that are multi-resistant to these medications, which has become a serious public health problem. One of the most prevalent species of pathogens in the hospital environment, causing infections, is the Gram-negative bacterium Acinetobacter baumannii. The World Health Organization identifies carbapenem-resistant A. baumannii as a priority in the development of new antibiotics, as these bacteria have resistance mechanisms that allow them to escape the most adverse classes of antibiotics. Therefore, in the present work, using bioinformatics and medicinal chemistry tools, we identified molecules with antimicrobial potential to be tested against A. baumannii. As strategy I, the computational construction of a hybrid molecule of antibiotics from the β-lactam and tetracycline classes, potentially effective against the penicillin-binding protein and the 30S ribosomal subunit of A. baumannii, was carried out. This hybrid molecule, called IM-TP, was used as a model for a similarity search in the PubChem database, in order to find molecules that retain the desirable characteristics of the hybrid model. The search found 295 molecular structures that retained characteristics of tetracyclines and β-lactams. As strategy II, through a partnership with Dr. Geisa Caprini Evaristo and the Center for Studies on Biomolecules Applied to Health (CEBio/FIOCRUZ-RO), they carried out in silico bioprospecting of the molecules present in the skin secretion of Phyllomedusa camba, a species of anuro, of which there are records of antimicrobial activity for its skin secretion. Using Strategy II, a total of 149 molecular structures were obtained from the PubChem database. The molecular structures found in strategies I and II were used in molecular docking against the penicillin-binding protein (PDB 3UDX) and the 30S ribosomal unit (PDB 7RYG) of A. baumannii. The molecular docking results highlighted promising molecules, both from strategy I and strategy II, with the potential to be tested in vitro against A. baumannii. For strategy I molecules, despite good of in silico results against both A. baumannii targets, no suppliers were found for these molecules, that made it impossible to perform in vitro antimicrobial activity assays against A. baumannii. Based on the in silico results of the molecules presented in the skin secretion of P. camba against the penicillin-binding protein and the 30S ribosomal subunit of A. baumannii, antimicrobial activity assays were carried out for the skin secretion of P. camba, which were discovered in MIC and IC50 data. For the skin secretion of P. camba against A. baumannii (ATCC 19606), the result was an MIC of 50 μg/mL and IC50 of 28.92 μg/mL, which seem promising when compared with information from the literature.

Thèses
1
  • KATIA PAULA FELIPIN
  • .

  • Leader : RICARDO DE GODOI MATTOS FERREIRA
  • MEMBRES DE LA BANQUE :
  • RICARDO DE GODOI MATTOS FERREIRA
  • SORAYA DOS SANTOS PEREIRA
  • ANDRÉ NICOLAU AQUIME GONÇALVES
  • LUIZA DE OLIVEIRA RAMOS PEREIRA
  • HELDER TAKASHI IMOTO NAKAYA
  • Data: 29 mai 2023


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  • The parasite Leishmania (Viannia) braziliensis is widely distributed in Brazil and is one of the main species associated with human cases of different forms of tegumentary leishmaniasis (LT) such as cutaneous leishmaniasis (CL) and mucosal leishmaniasis (LM) in which L. braziliensis is closely related. The mechanisms underlying the pathogenesis of TL are still not fully understood, but it is known that factors related to the host and the parasite act in a synergistic and relevant way to direct the response to the infection. In the host, the macrophage has a central relationship with the parasite and plays a fundamental role in the defense of the organism due to its ability to destroy intracellular parasites and present antigens. In the parasite, some intrinsic factors related to the species or even the strain analyzed are fundamental for the outcome of the disease, such as the presence of Leishmania RNA Virus 1 (LRV1), an endosymbiont virus that parasitizes some species of Leishmania that triggers a cascade of signals that lead to a more severe TL phenotype, such as LM. One of the strategies for understanding the factors associated with the immune response generated after Leishmania/host interaction is through the analysis of molecular patterns after infection. Thus, the gene expression profile in human monocyte-derived macrophages obtained from healthy donors infected with L. braziliensis positive (LbLRV1+) and negative (LbLRV1-) LRV1 was evaluated. For this, the microarray assay was used, and 162 genes differentially expressed were identified in the comparison LbLRV1+ vs. LbLRV1-, 126 of these with upregulation such as the type I and II interferons (INF) signaling pathway, oligoadenylate synthase OAS/RNAse L, non-genomic actions of vitamin D3 and RIG-I type receptors, and 36 genes with negative regulation which were not explored in this study. Type I interferon-related pathways (IFNI) and OAS results were validated by RT-qPCR and Th1/Th2/Th17 pattern cytokines were analyzed by Cytometric Bead Array (CBA) and enzyme-linked immunosorbent assay (EIA). The microarray results validated by RT-qPCR showed differential expression of genes related to INFI-mediated pathways with overexpression of different genes in cells infected with LbLRV1+ compared to LbLRV1- and negative control. No significant differences in cytokine levels between LbLRV1+ vs. LbLRV1- and the control in the CBA and EIA assay were found. The data suggest the activation of signaling pathways associated with the presence of LRV1 and include genes from pathways not yet reported so far. The study shows for the first time the activation of the OAS/RNAse L signaling pathway and the non-genomic actions of vitamin D3 when comparing infections with LbLRV1+ vs. LbLRV1- and the control. Initial results reinforce the role of LRV1 in directing the host's immune response after infection and its identification in patients with TL may be useful in screening to assess disease progression.

2
  • VALDISON PEREIRA DOS REIS
  • .

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • SORAYA DOS SANTOS PEREIRA
  • RODRIGO LABAT MARCOS
  • JACQUELINE DE ALMEIDA GONÇALVES SACHETT
  • LUCIANA LYRA CASAIS E SILVA
  • Data: 19 juin 2023


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  • Recent WHO data report the occurrence of up to 5 million envenoming caused by venomous snakes in the world, with up to 0.15 million fatalities, leaving 0.4 million victims with injuries irreversible. The Bothrops genus is responsible for more than 90% of snakebites in Brazil. To minimize its effects, the only specific treatment is serum therapy, which does not adequately reverse the local effects, making it necessary to search for adjuvant therapies associated with serum therapy to improve the treatment of these effects. In this context, photobiomodulation with LED is considered an important therapeutic resource with anti-inflammatory, analgesic, and healing effects. Despite its indication as an associative treatment, its mechanism of action is still the subject of studies. Thus, the general objective of this study was to analyze the oxidative redox potential of the application of photobiomodulation with LED and its action on the inflammatory profile of murine macrophages, stimulated with Bothrops jararacussu venom and bothropstoxins I and II. To this end, several methodological approaches were carried out, such as: cell marking and cell proliferation assays, analyzes of cell death by necrosis and apoptosis, dosage of cytokines and antioxidant enzymes, gene expression for markers of M1 and M2 phenotypes and PGE2 receptors as well as COX, PGE2 dosage and study membrane potential study. The results showed that photobiomodulation with LED modulated macrophages to the M2 phenotype, induced an increase in antioxidant enzymes and cytokine release, decreased cell death by necrosis and apoptosis, increased mitochondrial membrane potential, and modulated gene expression of PGE2 and COX 1 and 2 receptors. Together, the data obtained contribute to the understanding of the mechanism of action of Photobiomodulation with LED and reaffirm its important oxidative and modulatory redox characteristics, sufficiently capable of acting as necessary associative therapy with serum therapy to reduce the local effects of snakebite envenoming and may be used as a therapeutic resource teo the treatment of this important condition.

3
  • NAJARA AKIRA COSTA DOS SANTOS
  • .

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • MARIANA ROCHA DAVID
  • MARIA ANICE MUREB SALLUM
  • RAFAELA VIEIRA BRUNO
  • JANSEN FERNANDES MEDEIROS
  • MAISA DA SILVA ARAÚJO
  • NAJLA BENEVIDES MATOS
  • Data: 29 août 2023


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  • Anopheline gut bacterial community is an important factor against Plasmodium colonization, however there are few observations about the interaction among the microbiota, Plasmodium vivax and Anopheles darlingi. To better understand the interaction between P. vivax-An. darlingi, we proposed to study the composition and diversity of microbiota from midgut and salivary gland of lab-reared and field-caught An. darlingi, and to evaluate the impact of the microbiota on the survival of An. darlingi and artificial infection by P. vivax. Mosquitoes were obtained from An. darlingi colony of the PIVEM/Laboratório de Entomologia of Fiocruz Rondônia and field mosquitoes were collected by protected human landing collection. The V3-V4 and V4 hypervariable region of the 16S rRNA gene were sequenced to profile the microbiota composition of midguts and salivary glands of colonized and field-captured mosquitoes. The effect of microbiota on mosquito survival and in the sporogonic cycle of P. vivax was evaluated from antibiotic-treated and untreated mosquitoes. Mosquitoes infected by P. vivax were dissected at 7 and 14-day post-infection (dpi) for oocyst and sporozoite count, respectively. To analyze alpha-diversity, the Chao1, Shannon and Inverse Simpson indices were estimated, and for beta-diversity the weighted and unweighted Unifrac measures were assessed. Kaplan-Meier survival curves of treated and untreated mosquitoes were constructed and the hazard risk for each group was obtained by Cox Models. The effect of antibiotic treatment on the susceptibility of An. darlingi was evaluated by the Mann-Whitney test for oocyst and sporozoite intensity, and the prevalence determined by Chi-square. Anopheles darlingi microbiota data showed that the midgut and salivary gland had low diversity and dominance of a few bacterial taxa in microbiota communities. The salivary glands showed higher richness and diversity than midguts, regardless of sample origin. However, the salivary glands and midguts only showed dissimilarities in beta diversity between lab-reared mosquitoes. An intra-variability in taxa abundance was observed in the samples, and a high proportion of lab-reared mosquitoes shared a core microbiota, probably due to lab rear conditions. Acinetobacter and Pseudomonas were dominant in the tissues of lab-reared mosquitoes. Sequences of Wolbachia and Asaia were both found in the tissue of lab-reared mosquitoes; however, only Asaia was found in field-captured An. darlingi, but in low abundance. Antibiotic treatment was effective to reduce the bacterial load. The bacterial load reduction resulted an increase on the survival of treated mosquitoes and a protective effect > 63%, regardless the P. vivax infection. In this way, antibiotics may help to control bacterial proliferation and prevent mosquito death before 14 dpi. On the other hand, antibiotic treatment had no effect on the susceptibility of An. darlingi to P. vivax. This raise the question whether the An. darlingi-P.vivax-microbiota interaction could be different from what is known for others Plasmodium spp. and anopheline combinations.

4
  • BRUNO GILDO DALLA VECCHIA MORALES
  • .

  • Leader : FERNANDO BERTON ZANCHI
  • MEMBRES DE LA BANQUE :
  • CAROLINA BIONI GARCIA TELES
  • FERNANDO BERTON ZANCHI
  • JULIANE CORRÊA GLÓRIA
  • LUIS ANDRE MORAIS MARIÚBA
  • SPARTACO ASTOLFI FILHO
  • Data: 9 nov. 2023


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  • Plasmodium falciparum is known to cause severe malaria. Current treatment consists in artemisinin-based combination therapy, but resistance can lead to treatment failure. The knowledge of essential proteins of P. falciparum can be used on the search for new antimalarials, among these is shikimate dehydrogenase (SDH), part of a pathway responsible for the production of endogenous aromatic amino acids. SDH from P. falciparum (PfSDH) is unknown to the scientific community, therefore, this study aims to establish the first protocol for active PfSDH expression. Putative PfSDH nucleotide sequence was used to construct the optimized expression vector pET28a+PfSDH inserted in E. coli BL21(DE3). Optimal expression conditions were acquired by varying IPTG and time while temperature was fixed at 37 °C. Western Blot analysis was applied to verify appropriate PfSDH expression. Solubilization and purification started with lysis followed by double IMAC purification. SDS-PAGE was applied over various steps. Enzyme activity was measured spectrophotometrically by NADPH oxidation. Tanimoto coefficient and pharmacophore pattern similarity were applied to the in silico search for ligands employing the substrate DHS as template. Optimal PfSDH expression occur at 0.1 mM IPTG for 48 hours of growth at 37 °C and shaking at 200 rpm. Recombinant PfSDH obtained after purification was soluble, pure and its physiological catalysis was confirmed. Among all possible ligands obtained, 15 molecules had greater relevance when combining both methods applied. Thus, this study describes the first protocol for heterologous expression of PfSDH in soluble and active form, likewise instigating for a higher comprehension related to target-ligant interactions.

2022
Thèses
1
  • JACKSON ALVES DA SILVA QUEIROZ
  • Desenvolvimento de ensaio one step multiplex RT-qPCR quantitativo para monitoramento de carga viral de SARS-CoV-2 em indivíduos infectados com diferentes variantes

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • FELIPE GOMES NAVECA
  • SORAYA DOS SANTOS PEREIRA
  • Data: 17 févr. 2022


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  • COVID-19 has caused public health challenges due to the emergence of new variants, reinfections, and lack of treatment. The gold standard for diagnosing SARS-CoV-2 is qualitative RT-qPCR; however, the role of viral load quantification has not yet been fully investigated. Furthermore, studies correlating the persistence of SARS-CoV-2 and disease progression remain scarce. Thus, we aimed to develop a quantitative RT-qPCR assay for monitoring SARS-CoV-2 viral load in individuals infected with different variants. The assay standardization involved the absolute quantification method from a recombinant plasmid with the N gene of SARS-CoV-2 in biological matrix to construct a standard curve. Genome sequencing was performed using the study samples with Ct values <30 to determine SARS-CoV-2 variants and mutations. 244 samples with prior qualitative diagnosis were used for assay validation. The results demonstrated the possibility of quantifying up to 2.5 copies/reaction and analysis of the 244 patients with known results showed 100% agreement with an Anvisa registered qualitative assay. In addition, we performed viral load monitoring in 47 individuals on a weekly basis. During this evaluation, persistent viral load was detected for up to 24 days in 3 individuals. The Gamma variant was detected in 40.4% of the individuals, and this group had a higher initial viral load compared to the non-Gamma individuals. We selected 10 individuals hospitalized with severe COVID-19 and the result showed the presence of the Gamma variant in 70% of the cases, and in this same population a death rate of 50% was observed. With sequencing results it was possible to detect the variants B.1.1.33 (1/20), Gamma (13/20), P.1.4 (1/20) and Zeta (3/20), besides 57 mutations found in different viral genes, among these, the ORF9b:Q77E mutation not yet described in the databases. Conclusion: The results demonstrate the practical application of a highly sensitive quantitative test for SARS-CoV-2, which can be a useful tool in infection monitoring and highlights the importance of genomic surveillance to identify and monitor variants and mutations that may implicate in changing the viral load profile of SARS-CoV-2.

2
  • MILENA DANIELA SOUZA SILVA
  • ROLE OF PLA2S ISOLATED FROM Bothrops jararacussu VENOM OF NLRP3 INFLAMMASOME ACTIVATION IN HUMAN PERIPHERAL BLOOD MONONUCLEAR CELLS

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • FABIO HENRIQUE KWASNIEWSKI
  • LUCIANE ALARCÃO DIAS MELICIO
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • Data: 28 avr. 2022


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  • Phospholipases A2 (PLA2s) are proteins found in abundance in the venom of snakes of the genus Bothrops and play an important role in the inflammatory reaction and leukocyte activation. Monocytes and lymphocytes are cells of the immune system characterized by mediating and presenting effective responses during an inflammatory response. The NLRP3 inflammasome is a multiprotein complex that is present in cells of the immune system and is activated by stimuli such as pathogen-associated molecular patterns (PAMPs) and damageassociated molecular patterns (DAMPs). The action of PLA2s against human peripheral blood mononuclear cells (PBMCs) is still not well understood. In this sense, the present study aimed to evaluate the role of PLA2s (BthTX-I Lys49) or (BthTX-II Asp49) from Bothorps jararacussu on NLRP3 inflammasome activation. Thus, viability tests were carried out from human PBMCs in a period of 4 hours by DNA labeling with 7AAD. The results showed that at concentrations of 5 and 10 μg/mL there was no cell death. The relative gene expression of NLRP3, Caspase1, ASC, IL-1β and GAPDH (internal control) gene were performed by RT-qPCR. Furthermore, the protein expression of these components (NLRP3, Caspase-1, ASC), gasdermin D (GSDMD) and β-actin (internal control) was verified by Western Blot. The results obtained showed significant amplification when compared to the GAPDH control of NLRP3, ASC, Caspase-1 and IL-6 in 1 hour and, of IL-1β, in 2 hours. Protein expression was performed after 4 hours of PBMC stimulation, and the results obtained showed significant expression of NLRP3 and GSDMD inflammasome complex proteins. Another method of proving the activation of the NLRP3 inflammasome was the counting of punctas formed by the NLRP3 sensor component by immunofluorescence. Then, to verify the cell death dependent on the activation of caspase-1, pyroptosis, LDH was measured in the supernatant of the PBMCs incubated with the different stimuli after 4 and 6 hours. The release of LDH occurred in 6 hours, as well as the expression of GSDMD, suggesting that the release of this molecule occurs due to the formation of pores in the membrane, a consequence of pyroptosis. Taken together, the data obtained so far show that the PLA2s, BthTX-I and BthTX-II, isolated from Bothrops jararacussu venom, activate the NLRP3 inflammasome complex culminating in the formation of membrane pores through GSDMD in human PBMCS that contribute to the inflammatory response observed in envenomation by this snake.

3
  • AUREA VIEIRA TEIXEIRA
  • BAIT STATIONS AS A TOOL FOR THE CONTROL OF Aedes aegypti (DIPTERA: CULICIDAE): EVALUATION OF MODELS AND COMPONENTS OF SUGAR TOXIC ATTRACTIVE BAITS (ATSB) IN THE LABORATORY

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • ELIS PAULA DE ALMEIDA BATISTA
  • ROSEMARY APARECIDA ROQUE
  • Data: 20 mai 2022
    Ata de defesa assinada:


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  • Aedes aegypti is an important vector of arboviruses such as dengue, yellow fever, chikungunya and Zika, and the absence of vaccines or treatments for most of them makes vector control the main alternative to reduce the transmission. Among vector control methods, chemical control is widely used, and includes new approaches, such as Attractive Toxic Sugar Baits (ATSBs). The ATSBs aim to supply an insecticide in an attractive sugar solution, using the natural sugar feeding habit by both males and females to induce mosquitoes to ingest the bait. In addition to the versatility of this bait in relation to its composition, previous studies have indicated the potential of offering ATSB using bait stations (BSs), making it an additional lowcost tool. Therefore, the objectives of this work were to evaluate different models of BSs in the laboratory and to estimate the Lethal Concentrations (LCs) of dinotefuran (DNT) alone and combined with ivermectin (IVM), in males and females of Ae. aegypti. The BS models were: Artificial plant, pet bottle, ovitrap and resting box, sprayed with two solutions: 10% sucrose (SB) and 10% sucrose and guava juice (ASB). The experiments were carried out in screened cages with 100 fasted mosquitoes (24h males and 48h females), during 6 hours. Later the engorged mosquitoes were separated according to the degree of engorgement. To calculate the DNT LCs, ATSBs were prepared with 70% sucrose and increasing concentrations of DNT. For the combination of insecticides experiments, increasing concentrations of DNT were prepared combined with 0.312ppm IVM and increasing concentrations of IVM combined with 1ppm of DNT. Subsequently, synergism ratios were calculated. The engorgement of the ASB (7.0 - 40%) was much lower than SB baits (50 - 80%). All BSs can be used under the conditions tested, as there were no differences in engorgement and degrees of engorgement of mosquitoes between them. ATSBs with DNT did not affect general engorgement or degree of engorgement that did not varied with increasing concentrations of this insecticide. The mortality of females, in general, was lower than that of males, especially at low concentrations and the CL90 of males and females was 35.6 and 56.0ppm, respectively. The combination of insecticides in ATSBs did not affect the engorgement (80%) and a synergistic effect was observed in mosquito mortality, especially for the combination of IVM + DNT in low concentration. SB and ATSB baits applied to all tested BSs were engorged by males and females of Ae. aegypti. In addition, the combination of insecticides IVM+DNT significantly reduced the CLs of insecticides required for use in ATSBs

4
  • ANJO GABRIEL CARVALHO
  • PHENOTYPIC AND MOLECULAR IDENTIFICATION AND CHARACTERIZATION OF Streptococcus agalactiae ISOLATED IN PREGNANT WOMEN IN  PORTO VELHO-RONDÔNIA REGION

  • Leader : NAJLA BENEVIDES MATOS
  • MEMBRES DE LA BANQUE :
  • ROSANA ROCHA BARROS
  • TATIANA DE CASTRO ABREU PINTO
  • NAJLA BENEVIDES MATOS
  • Data: 23 mai 2022
    Ata de defesa assinada:


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  • Streptococcus agalactiae (GBS) is the main etiological agent of neonatal infections today, and colonization of the rectovaginal site of pregnant women is the main risk factor for the development of the pathology. This bacterial species is classified into ten serotypes (Ia, Ib and II-IX), which vary in terms of prevalence, geographic and temporal distribution and degree of virulence. GBS exhibits a repertoire of surface proteins essential for adhering to and invading host tissues, as well as hindering their recognition by the immune system and ability to form bacterial biofilms. In addition, an increase in the rate of resistance to prophylactic antimicrobials has been reported. Brazil fits in the list of countries where GBS is not recognized as a relevant etiological agent of neonatal diseases. Therefore, the present study aimed to carry out the identification and phenotypic and molecular characterization of serotypes, virulence factors and antimicrobial resistance of Streptococcus agalactiae isolates in pregnant women in the city of Porto Velho-RO. GBS samples were isolated from rectovaginal cultures of pregnant women aged 35 to 37 weeks attended in the basic health network. GBS was identified in the samples by PCR (Polymerase Chain Reaction) with specific primers for the cfb gene, and later by sequencing the 16S ribosomal region. Serotyping was performed by conventional multiplex PCR assay. The genes associated with virulence (hylB, cylE, lmb, bac, bca, scpB and hvgA) and resistance (erm(A), erm(B) and mef(A/E)) were evaluated by PCR. The antimicrobial susceptibility profile was determined by the disk-diffusion method. The ability to form bacterial biofilms in-vitro was also measured. Of the total number of pregnant women included in the study, 23% (114/496) were positive for GBS colonization, and of these it was possible to recover 85 isolates. We evidenced the presence of six serotypes in the region, with 36.5% (31/85) belonging to Ia, 14.1% (12/85) to Ib and II, 11.8% (10/85) to III, 15 .3% (13/85) at V and 8.2% (7/85) at VI. Regarding virulence factors, the following frequencies were observed: scpB in 100% (85/85), lmb in 97.6% (83/58), bca in 84.7% (72/85), hylB in 64.7% (55/85), clyE in 60% (51/85) and bac in 57.6% (49/58). A high rate of resistance to tetracycline, erythromycin and clindamycin was observed with 74.1% (63/85), 14.1% (12/85) and 3.5% (3/85), respectively. Already 100% (85/85) of the isolates were sensitive to penicillin, ampicillin, cefazillin, ceftriaxone, chloramphenicol and vancomycin. Regarding resistance genes, it was observed that of the isolates not sensitive to macrolides and lincosamines, 64.7% (11/17) had the erm(A) gene, 41.2% (7/17) had the erm(B) gene, and 88.2% (14/17) carried the mef(A/E) gene. It was shown that 91.8% (78/85) of the isolates had a strong/moderate ability to produce biofilms. It was evidenced that 100% of the serotype III isolates are carriers of the hvgA gene and, therefore, classified as hypervirulent. The second description of serotype VI in Brazil stands out here, with a higher prevalence rate than that found previously. The present study points to a high rate of genes associated with virulence and resistance in the isolates from the region, associated with a homogeneous spread among the serotypes found, and underlines the importance of establishing active surveillance systems to understand the infections caused by GBS.

5
  • MICHELLI SANTOS DA SILVA
  • USE light-emitting diodes (LEDs) in the capture of  sand flies (Diptera, Psychodidae), molecular detection of leishmania and blood meal sources used by females in a locality in the municipality of Porto Velho, Rondônia, Brazil

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • ANDREY JOSÉ DE ANDRADE
  • FELIEP DUTRA RÊGO
  • JANSEN FERNANDES MEDEIROS
  • Data: 27 mai 2022
    Ata de defesa assinada:


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  • Sand flies are dipteran insects that are important for acting as vectors of pathogens, including Leishmania species. One of the main strategies to understand these insects is based on monitoring from entomological surveys. Light traps are among the main methods for capturing sand fly species as they generally respond to light stimuli. In recent years, studies have effectively adapted light-emitting diodes (LEDs) to traps. However, no study has evaluated the effectiveness of LEDs in capturing of sand flies in the Amazon biome. Based on this assumption, the present study aims to evaluate the influence of LEDs on the capture and diversity of sand flies in Porto Velho, Rondônia, Brazil, in addition to identifying potential Leishmania vectors and the blood meal sources used by females. Thus, sand flies were collected with HP light traps using blue, green, red and ultraviolet LEDs, as well as incandescent light as a control using the Latin square method. A total of 1,993 individuals were collected, distributed in 52 species belonging to 12 genera. The most abundant species in this study were Trichophoromyia ubiquitalis (n=365), Bichromomyia flaviscutellata (222), Psychodopygus davisi (148), Nyssomyia Antunesi complex (128). The incandescent light HP captured the largest number of individuals (n=590), followed by blue (471), green (452), ultraviolet (281) and red (150) LED traps. A PERMANOVA test was applied and there was no difference in the composition of the sandfly fauna by the different light sources (Pseudo F = 1.29, p = 0.14). This same pattern was also observed when applying the NMDS, in which no difference was observed in the composition of the sandfly species (Stress 0.18). The number of males 1,057 (54.4%) was higher in relation to females 887 (45.6%) in most light sources, but a greater number of females in relation to males was observed in the trap with the blue LED. For the natural infection, 32 pools of 275 females of 10 species were analyzed. None of the pools was positive for Leishmania detection, however amplification was observed for Endotrypanum spp. referring to the pool of Ny. fraihai. The following feeding sources were observed: Tamandua tetradactyla and Choloepus hoffmanni in females from the Antunesi complex (12) and in Ny. richardwardi (1), Proechimys gardneri in Bi. flaviscutellata (2) and Homo sapiens in Bi. flaviscutellata (1). The data obtained indicate that blue and green LEDs can be as efficient as incandescent light, that the sandflies in this study area use several blood meal sources and that other trypanosomatid species can be found in the sand flies. The data obtained can help in future studies in the region.

6
  • MARLEI NOVAES DE SOUSA
  • EVALUATION OF ANTIMICROBIAL ACTIVITY OF SNAKE VENOM Bothrops jararacussu AND BIOCHEMICAL CHARACTERIZATION OF AN ISOLATED METALOPROTEASE


  • Leader : ANDREIMAR MARTINS SOARES
  • MEMBRES DE LA BANQUE :
  • ANDREIMAR MARTINS SOARES
  • NAJLA BENEVIDES MATOS
  • STELLA REGINA ZAMUNER
  • Data: 27 juin 2022


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  • Snake venoms contain a mixture of molecules capable of mediating directly or indirectly inflammatory, hemorrhagic, neurotoxic, myotoxic and other cellular changes. In this context the metalloproteases, which are enzymes highly toxic profile, zinc dependent and of variable molecular mass, playing a relevant role in the complex and multifactorial response characteristic of the snake poisoning. In this pointing of view, several studies with snake venoms seek to find substances with possible potential therapeutic application for the development and drug improvement, demonstrating a beneficial characteristic for these biological molecules. Therefore, this work aims to evaluate in vitro the antimicrobial action from the Bothrops jararacussu snake venom, as well as from an isolated metalloprotease. To obtain the metalloprotease, it was necessary to fractionate the venom by liquid chromatography, using a CM-Sepharose-type ion-exchange column and the choice of fraction corresponding to the protein of interest was based on its electrophoretic characteristics (SDS-PAGE), molecular mass (mass spectrometry) and enzyme activity (fibrinogenolytic and caseinolytic). The results showed that the metalloprotease was purified with a satisfactory yield and adequate purity, representing about 5.4% of the total venom and presenting a single polypeptide chain with a molecular mass between 23 and 24 kDa, classifying it as a P1 class metalloprotease. This enzyme showed metal ion-dependent proteolytic activity, confirming that it belongs to the class of metalloproteases from snake venoms. It was also observed that this metalloprotease was capable of inducing hemorrhage in vivo in the cremaster muscle of mice analyzed by intravital microscopy. In antimicrobial activities, Bothrops jararacussu venom, showed inhibition at some concentrations tested in two ATCCs strains (100, 50, 25, 12.5 μL/mL for Klebsiella pneumoniae and 100 and 50 μL/mL for Stapylococcus aureus), however, the different concentrations of metalloprotease tested were not able to inhibit the bacterial growth. Finally, the data presented in this study support the biochemical and functional characterization of the protein under study, but they differ from other published studies regarding antimicrobial activity. Other work must be carried out to verify the pharmacological potential of metalloproteases, as well as other components of snake venom, which have a significant contribution to scientific knowledge with important biotechnological applications for human health.

7
  • SAYONARA DOS REIS
  • x

  • Leader : GABRIEL EDUARDO MELIM FERREIRA
  • MEMBRES DE LA BANQUE :
  • ANA CAROLINA STOCCO DE LIMA
  • EDUARDO DE CASTRO FERREIRA
  • GABRIEL EDUARDO MELIM FERREIRA
  • Data: 26 juil. 2022
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  • Leishmaniasis is an infectious, non-contagious disease caused by the parasite of de genus Leishmania. The North Region has the highest number cases of Tegumentary Leishmaniasis (TL) in Brazil, and in the state of Rondônia, the seven dermotropic species of this parasite recorded in the country were identified. However, the species identification is still a challenge for laboratory routines. In this context, the present work seeks to evaluate the identification of Leishmania spp. in samples with an inconclusive enzymatic restriction profile or identified as L. guyanensis, using RFLP approaches and nucleotide sequence analysis of a region of the hsp70 gene. Two groups of samples from patients diagnosed with TL by the Genetic Epidemiology Laboratory between the period 2012 to 2019 were selected, divided into samples identified by RFLP of L. guyanensis (group I) and samples with an inclusive restriction profile (group II). The samples were submitted to conventional PCR for 234bp hsp70 target, and then sent to the sequencing platform. The hsp70-PCR-RFLP assays were performed using a panel of three restriction enzymes (HaeIII, BstUI and MboI). Among the 110 samples selected, only 66 tested positive for PCR. Of these, 30 samples from group I and 36 samples from group II. Analyzing the sequences obtained by sequencing, it was possible to identify all species from all samples using the BLAST algorithm. Analyzing the results obtained from the two techniques, in group I, three species were identified, L. braziliensis, L. guyanensis and L. lindenbergi, in group II, five species were identified, L. braziliensis, L. guyanensis, L. amazonensis, L. naiffi and L. infantum. In 13 sample from 13 patients did not obtain results by RFLP method were identified as Leishmania spp. While more studies are still needed connecting Leishmania species to response to treatment and clinical manifestations of this disease, the identification of species is recommended to define the best follow-up and therapeutic management. In great biodiversity regions as the Amazon, the diversity of species present makes this step essential for a better understanding of epidemiology and prognosis of disease. The results obtained performed demonstrate that RFLP method and the analyzing the nucleotides of the molecular target of this study, it is possible to identify Leishmania species recorded in Brazil. Despite the limitations presented, either in terms of resolution or laboratory structure, both approaches can be used in a complementary way to identify the Leishmania species evaluated

8
  • SIBELE ANDRADE ROBERTO
  • .

  • Leader : SORAYA DOS SANTOS PEREIRA
  • MEMBRES DE LA BANQUE :
  • LUIS ANDRE MORAIS MARIÚBA
  • LUIZ FERNANDO ALMEIDA MACHADO
  • SORAYA DOS SANTOS PEREIRA
  • Data: 26 sept. 2022
    Ata de defesa assinada:


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  • Human T-lymphotropic virus type 1 (HTLV-1) is one of the etiologic agents of T-cell leukemia/lymphoma in adults and of HTLV-1-associated myelopathy, called tropical spastic paraparesis (HAM/TSP). About 5-10 million individuals are infected with the virus worldwide. In Brazil, the tests applied for the diagnosis of the disease are restricted to the screening steps in blood donor samples. Thus, the availability of supplies to assist in the detection of infection, as well as its implementation at the public health level aimed at the Unified Health System (SUS) would be an alternative to facilitate the diagnosis of HTLV-1 infection. The use of molecules with high stability and ability to recognize molecular targets in a specific and sensitive way is a criterion for the effectiveness of diagnostic tests. From this perspective, camelid VHHs stand out for having such characteristics. Therefore, this work proposes the use of anti-p24 VHHs for the construction of biosensors applicable to the development of assays for the diagnosis of active infection caused by the HTLV-1 virus. From a previous characterization, after sequencing, it was possible to select 3 clones of VHHs (anti-p24/C11, anti-p24/C52 and anti-p24/C86). However, only clones VHH-11 and VHH-52 were effectively recombined in pET-22b(+) vector and then subjected to expression standardization in Escherichia coli strain BL21(DE3) and SHuffle® T7 Express. Of the expression conditions evaluated to obtain VHH C52 in a soluble form, the one that proved to be more effective was with induction at 30ºC and 0.3 mM of IPTG in the SHuffle® T7 Express strain. After purification by immobilized metal ion affinity chromatography (IMAC), Western blot and ELISA results confirmed, respectively, the presence of the VHH-histag and the permanence of its reactivity against p24. From the synthesis of gold nanoparticles (AuNPs) by the Turkevich method and characterization by transmission electron microscopy (TEM), it was possible to establish the bioconjugation conditions of VHH-anti-p24/52 at a concentration of 8 μg and pH 9, to AuNPs, in the presence of 75 mM of the acrylic acid stabilizing agent N-hydroxysuccinimide-ester (NHS). The immunoreactivity of biosensors by DOT BLOT assay demonstrated the ability of bioconjugates to recognize different concentrations of recombinant HTLV-1 p24. The results achieved demonstrated the potential of VHH-anti-p24/52, as an input for the constitution of optical immunosensors applicable to the detection of HTLV-1 p24 protein. Still in this work, the application of VHH constituting an electrochemical biosensor was explored, from the coupling of VHH anti p24/52 to gold electrodes. In preliminary tests, it was possible to obtain a sensor capable of detecting up to 1 ng/μL of HTLV-I recombinant p24. The results achieved demonstrate the potential of anti-p24 VHHs, however, additional tests are needed to determine the application of VHH-type antibodies constituting optical and electrochemical biosensors for the construction of different devices for detecting p24 of the HTLV-1 virus.

9
  • ALESSANDRA DA SILVA BASTOS
  • .

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • LUIZ GUILHERME SOARES DA ROCHA BAUZER
  • ALEXANDRE DE ALMEIDA E SILVA
  • MAISA DA SILVA ARAÚJO
  • Data: 5 oct. 2022
    Ata de defesa assinada:


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  • In mosquitoes, behavioral patterns with circadian periodicity could be observed
    through locomotor activity, because it corresponds to a behavior such as foraging
    mating and oviposition. Habits that are fundamental to its life cycle and that are
    related to the pathogens transmission to humans. In order to assess the locomotor
    activity of the main malaria vector in the Amazon region, Anopheles darlingi, this
    study aimed to (i) compare the locomotor activity between inseminated and not
    inseminated females; (ii) to evaluate the effect of the blood feeding on the locomotor
    activity of inseminated and not inseminated females; (iii) to evaluate the locomotor
    activity of mosquitoes infected and not infected by Plasmodium vivax. For the
    experiments, An. darlingi females from the Platform of Production and Infection of
    Malaria Vectors – PIVEM/FIOCRUZ – RO, with six days of age and treated with 15%
    honey solution were used. The experimental groups were separated in not
    inseminated females (NINS), generated from cages which male mosquitoes were
    removed immediately after emergence, and from inseminated females (INS) from
    cages which there was copulation. Subsequently, the other groups were formed by
    NINS and INS females without and with blood feeding (NINS SRS x NINS CRS; INS
    SRS x INS CRS). And finally, females fed with blood sample from a malaria donor (P.
    vivax+
    ) and females fed an aliquot of this sample submitted to inactivation of the
    parasites (42oC for 30 min) (P. vivax-

    ). Blood feeding was performed through the
    artificial membrane feeding Hemotek® after previous fasting. The monitoring of
    locomotor activity were performed in the Flybox equipment for up to six days, with the
    internal photoperiod in LD with 12 h of light and 12 h of dark. The locomotion activity
    was determined from the images of FlyBox through the software WebCan Image
    Save – 1.11, converted into video and quantified through PySoLo (v1.1) and
    analyzed the periodicity, rhythmicity in the software MatLab® version R2015b. The
    graphs generated in Excel and the statistical analysis performed in the GraphPad
    Prism software version 9.1. 0. The t Student and Mann-Whitney test were applied to
    compare the average locomotor activity in the time intervals: 24h, photophase,
    scotophase, ZT12 and ZT0. Circadian periodicity was close to 24 h and rhythmicity
    was above 50%. The locomotor activity was bimodal pattern, with a main peak called
    nocturnal peak (ZT12) and a second less pronounced peak called diurnal peak
    (ZT0). When comparing the insemination states, a reduction in the activity of the INS
    group was recorded in ZT12 the first two days and the photophase of the third day in
    relation to NINS group. The activity of the NINS CRS group was reduced in the 24-
    hour cycle, scotophase and ZT12 the first two days of analysis, to first the
    photophase and in the ZT0 of the three days of analysis, returning to an activity
    similar to NINS SRS group on the third day. For the INS CRS group there was a
    reduction in activity in the 24-hour cycle, phtophase and scotophase of the first and
    third day, and in ZT0 and ZT12 of the three days of analyzeis in relation to the INS
    SRS. In the group P. vivax+ the activity was reduced in the photophase of the first
    and second day. We conclude that, like other vectors of the genus, An. darlingi has
    nocturnal habits and that physiological conditions influence the locomotor activity of
    this vector.

Thèses
1
  • LUIS PAULO COSTA DE CARVALHO
  • ,

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • JANSEN FERNANDES MEDEIROS
  • RUTH LEILA FERREIRA KEPPLER
  • MARIA CLARA ALVES SANTARÉM
  • CARLA G GAZORLA
  • FRANCINALDO SOARES SILVA
  • Data: 29 avr. 2022
    Ata de defesa assinada:


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  • Culicoides biting midges are vectors of arboviruses, including Oropouche Virus and
    Bluetongue Virus. These insects are found in forest areas, but deforestation can contribute to
    the adaptation of vectors to anthropogenic environments. Much information about this group
    remains unknown, especially in Rondônia, where there are few studies. This study aims to
    assess the diversity of biting midges in fragmented forest environments; evaluate the
    identification of cryptic species, with emphasis on vectors, through the DNA Barcode tool;
    check the blood meals used by female midges. The collections were carried out in the Jamari
    National Forest in 2018. In total, 48 species of 1,480 individuals were identified, distributed in
    5 subgenera: Anilomyia, Avaritia, Haematomyidium, Hoffmania and Mataemyia, and 13
    informal species groups: acotylus, carpenteri, dasyophrus, debilipalpis, eublepharus, fluvialis,
    guttatus, hylas, leoni, limai, pachymerus, paraensis and reticulatus. The most abundant species
    were Culicoides pseudodiabolicus (457 - 30.88%), C. glabrior (154 - 10.41%), C. debilipalpis
    (137 - 9.26%), C. coutinhoi (97 - 6.55% ), C. quasiparaensis (63 - 4.26%) and C. brownei (57
    - 3.85%). Fifteen new species occurrence records were signed for the state of Rondônia. The
    Santa Maria trail was more diverse (45 species out of 1,007 individuals) compared to the Potosi
    trail (35 species out of 473 individuals). DNA was extracted and PCR performed from 455
    engorged females, and identified in 186 individuals, with a source blood meals from Tamandua
    tetradactyla (Anteater), Pithecia irrorata (Gray’s bald-faced saki), Choloepus hoffmanni
    (Hoffmann’s two-toed sloth), Choloepus didactylus (Southern two-toed sloth), Psophia viridis
    (Trumpeter), Ramphastos tucanus tucanus (Toucan), Pauxi sp. (Curassow), Ateles chamek
    (Spider monkey) and Homo sapiens (human). 186 sequences of 19 Culicoides species were
    obtained and submitted to DNA barcoding analysis, directed to the COI gene, and resulted in
    an alignment containing 84 haplotypes with a size of 558 bp. For two specimens it was not
    possible to identify morphologically at a specific level due to problems in assembling the
    individuals, but when analyzed in the phylogenetic tree together with other species, these
    individuals grouped with the clades C. pseudodiabolicus and C. debilipalpis, demonstrating
    that such specimens belong to such a taxonomic unit. The DNA barcoding tool has been shown
    to be capable of rapid and accurate identification of species of organisms using one or a few
    short standardized regions of DNA and has been widely used for effective identification of other
    groups at a specific level as well. The expansion of knowledge about the diversity of midges,
    ecology, feeding sources and molecular identification tools can provide important information
    for understanding the ecological, epidemiological and taxonomic profile of these insects in the
    Amazon.

2
  • JESSICA AMARAL LOPES
  • PAPEL DA BthTX-I E BthTX-II ISOLADAS DO VENENO DE Bothrops jararacussu NA POLARIZAÇÃO E FUNÇÃO DE PBMCs

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • ADRIANA LIMA VALLOCHI
  • FABIO HENRIQUE KWASNIEWSKI
  • GUSTAVO BATISTA DE MENEZES
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • LUCIANE ALARCÃO DIAS MELICIO
  • Data: 16 mai 2022


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  • Bothrops venom has a large amount of phospholipase A2 enzymes (PLA2s) that are responsible for myotoxicity, inflammatory reaction, and leukocyte activation in envenomation. PLA2s are proteins that have enzymatic activity and can hydrolyze phospholipids at the sn-2 position, releasing fatty acids and lysophospholipids, precursors of eicosanoids important mediators of inflammatory conditions. It has already been demonstrated in the literature that leukocytes (neutrophils and macrophages) contribute to the development of the inflammatory response induced by bothropic venoms and the PLA2s isolated from these venoms contribute to this process. However, the role that these enzymes play in the activation and function of human peripheral blood mononuclear cells (PBMCs) is not known. Bearing this in mind and knowing that the local inflammatory condition is persistent in envenoming caused by snakes of the Bothrops genus, the present study aimed to show how the two secreted isolated PLA2s from the venom of Bothrops jararacussu (BthTX-I and BthTXII) affect the functioning and polarization of PBMCs during the period of cell differentiation. For this, PBMCs were isolated and stimulated with RPMI (negative control), LPS+IFN-γ (positive control for M1, classical macropahges), IL-4+IL-13 (positive control for M2, alternative macrophages), BthTX-I or BthTX-II for 7 days. The following parameters were analyzed: cell morphology, phenotype, gene expression by RT-qPCR of pro-inflammatory (TNF-α, IL-6, IL-12 and iNOS) and anti-inflammatory (TGF-β, IL-10 and Arg-1) mediators corresponding to each phenotype and functional cell assays such as formation of lipid bodies (CLs) and phagocytosis. The morphological assays showed that the PBMCs on the 1st day of differentiation showed less complexity when compared to the 7th day. The immunophenotyping of PBMCs stimulated with BthTX-I and BthTX-II showed an increase in polarization for the antiinflammatory profile on the 1st day and this pattern was maintained on the 3rd, 5th and 7t day, demonstrating that immunophenotyping alone is not a parameter to analyze the polarization. The gene expression of pro-inflammatory and anti-inflammatory mediators was detected throughout the differentiation period studied demonstrating high plasticity of these cells and the importance of toxins (BthTX-I BthTX-II) in modulating these profiles. Functional assays of CL formation demonstrated that PBMCs stimulated with the toxins exhibited an increase in the number of CLs both within 1 hour and at the end of the 7th day. Another functional parameter, phagocytosis of zymosan particles was increased by the two toxins within 1 hour. Thus, the present study indicates for the first time that even evaluating during the entire period of cell differentiation and, taking into account the morphological, genetic and protein expression, phenotype and functional assays, both secreted PLA2s promote both polarization profiles in the PBMCs, exhibiting great cellular plasticity, which may be crucial to try to minimize the local damage caused by these bothropstoxins.

3
  • CHARLES NUNES BOENO
  • x

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • LUCIANA LYRA CASAIS E SILVA
  • ADRIANA LIMA VALLOCHI
  • FABIO HENRIQUE KWASNIEWSKI
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • LAURA CRISTINA ANA LEIVA
  • Data: 1 juil. 2022


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  •  

    Phospholipases A2 (PLA2s) are proteins found in snake venoms that have hemolytic,
    anticoagulant, myotoxic, edematogenic, bactericidal and inflammatory actions. In
    Bothrops jararacussu snake venom, these proteins make up about 30% of the venom
    and two types were isolated, BthTX-I, an enzyme that has a lysine at position 49
    (Lys49-PLA2) and BthTX-II, an enzyme that has an aspartate at position 49 (Asp49-
    PLA2). These toxins are myotoxic and inflammatory. The NLRP3 inflammasome is an
    intracytoplasmic platform that recognizes molecules released when tissue is damaged.
    After this recognition, caspase-1 is activated and IL-1β is released, contributing to the
    inflammatory response observed in cases of snakebite envenomation. The objective
    of this study was to verify the action of these PLA2s, BthTX-I and BthTX-II, in the
    activation of the NLRP3 inflammasome, in an experimental envenomation model in
    mice and, in vitro, in elicited murine macrophages as well as in C2C12 myoblasts. For
    this, the animals received an intramuscular injection of BthTX-I or sterile saline
    solution. Serum was collected for measurement of creatine kinase (CK), lactate
    dehydrogenase (LDH) and IL-1β. The muscle was removed for Western blot and gene
    expression by RTq-PCR for the NLRP3 inflammasome. Leukocyte influx in muscle was
    also evaluated by intravital microscopy. In macrophages stimulated with BthTX-I and
    BthTX-II and in C2C12 myoblasts, the NLRP3 inflammasome, the P2X7 receptor, the
    type 2 (EP2) and type 4 (EP4) prostaglandin receptors and the cyclooxygenase (COX)
    pathway were evaluated by RTq-PCR, indirect immunofluorescence, Western blot in
    the presence and absence of EP2 and EP4 antagonists. The data obtained showed
    that BthTX-I induced leukocyte influx into the muscle of the animals, observed under
    microscopy, as well as the release of LDH and CK into the plasma of the animals. The
    treatment of the animals with A438079, a P2X7 receptor antagonist, did not change
    these parameters. BthTX-I induced the activation of the NLRP3 inflammasome in the
    muscle, but the participation of P2X7R in this effect was not observed. Together, the
    results showed for the first time that BthTX-I in gastrocnemius muscle induces
    inflammation and, consequently, NLRP3 inflammasome activation, caspase-1
    activation and IL-1β release. In elicited and stimulated macrophages, the two toxins
    induced gene expression of the inflammasome components NLRP3, P2X7, cytokines
    (IL-1β, IL-6 and IL18), COX-1 and COX-2, EP2 and EP4. On the other hand, these
    findings were not observed in C2C12 myoblasts. Treatment of macrophages with
    antagonists for EP2 (PF04418948) and EP4 (GW627368X) abolished this effect. The
    two toxins also induced protein expression of NLRP3 inflammasome components and
    treatment with the antagonists reduced this effect. Activation of the NLRP3
    inflammasome was confirmed by immunofluorescence assay and by quantification of
    IL-1β released by macrophages. By treating macrophages with antagonists for EP2
    (PF04418948) and EP4 (GW627368X) it was possible to confirm the participation of
    PGE2 receptors in this effect. Together, the data obtained show that the muscle
    damage caused by BthTX-I in vivo triggers the activation of the NLRP3 inflammasome
    complex. In vitro, BthTX-I and BthTX-II induce macrophages to activate the NLRP3
    inflammasome with the participation of the COX pathway and PGE2 receptors,
    contributing to the harmful effect observed in envenomation.

4
  • MARCELA CRISTINA DE SOUZA SILVA
  • .

  • Leader : SORAYA DOS SANTOS PEREIRA
  • MEMBRES DE LA BANQUE :
  • CARLOS DELFIN CHASVEZ OLORTEGUI
  • ANDREA QUEIROZ MARANHÃO
  • GILVAN PESSOA FURTADO
  • MARCOS ROBERTO DE MATTOS FONTES
  • SORAYA DOS SANTOS PEREIRA
  • Data: 15 août 2022


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  • Driven by many advances in immunology and synthetic biology, different approaches and antibody formats are investigated for their ability to neutralize animal toxins. The Camelid Antibody Heavy Chain Variable Domain (VHH) or nanobody presents itself as a promising tool for diagnosis and therapy. VHH has a small size (~15 kDa), ease of genetic manipulation, low immunogenicity, ability to penetrate dense tissues, recognition of normally inaccessible epitopes and stability to changes in temperature and pH. Its peculiar characteristics have leveraged studies for its application regarding the neutralization of animal toxins. The high number of cases and the sequelae caused by snakebites make this condition a serious public health problem. Although serum therapy is effective against systemic damage, it has limitations in neutralizing the venom at the bite site. In addition, serotherapy agents may develop hypersensitivity reactions due to their heterologous nature. Thus, the need for more efficient, homogeneous and safe preparations has instigated the search for alternative processes and products for the treatment of snake envenomation. Therefore, this work proposes the in silico and in vitro characterization of Lama glama nanobodies previously selected against the metalloproteinase P-I, BjussuMP-II, from the venom of B. jararacussu. For this, camelid nanobodies against BjussuMP-II were previously selected using Phage Display technology. After gene characterization by sequencing and in silico analysis, 7 distinct clonal profiles were identified. In order to obtain soluble nanobodies for further assays, the gene sequences of the 7 clones were recombined in pET-22b(+) vector and expressed in E.coli bacteria strain BL21(DE3). The immunoreactivity of clones against BjussuMP-II was evaluated by enzyme immunoassay, which was maintained after purification by cobalt affinity chromatography column. The specificity of the nanobodies was also determined by Western blot, with recognition against BjussuMP-II and B. jararacussu total venom. In the evaluation of the proteolytic activity of BjussuMP-II on casein, VHH OL960543 showed inhibitory potential on the proteolytic activity of BjussuMP-II in all tested ratios. Through in vitro tests, it was possible to observe a 25% reduction in the levels of LDH released by murine endothelial cells (t-END), demonstrating the ability of VHH OL960543 to neutralize part of the toxic effects triggered by BjussuMP-II. In silico analysis, by molecular docking, of VHHs with BjussuMP-II demonstrated the possible interaction with amino acids present in the catalytic site, as well as in regions of great importance for the conformation and stability of the toxin of interest. CD spectra for VHH OL960543 estimated a secondary structure of 5.3% α helix, 44.7% β strand (3.3% left twisted; 29.2% relaxed; 12.2% right twisted) and 11.2% turn, in agreement with the theoretical structural model generated for the sequence (4.5% of α helix, 52.2% of β strand and 16.4% of turn), with calculated melting temperature (TM ) of 56.4º C. The results generated will be able to direct specific studies in the perspective of producing useful tools for the development of immunobiologicals based on camelid nanobodies.

5
  • FABIANNE ARAÚJO GOMES DOS SANTOS ALVES
  • MOLECULAR EVALUATION HEPATITIS B AND DELTA IN POPULATION INDIGENOUS WARI-AMAZONIA OCIDENTAL

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • SORAYA DOS SANTOS PEREIRA
  • LIVIA MELO VILLAR
  • MAURO SHUGIRO TADA
  • MICHELE OLIVEIRA DOS SANTOS
  • Data: 27 oct. 2022
    Ata de defesa assinada:


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  • Hepatitis B is considered an important public health problem worldwide, the chronic form of the disease caused by the hepatitis B virus (HBV) is considered the main cause of cirrhosis and cellular hepatocarcinoma. HBV is a DNA virus, of the Hepadnaviridae family and it is estimated that 257 million people are chronically infected by the virus. Classified into 10 genotypes (A-J) and 24 subgenotypes (A1-A3, B1-B5, C1-C6, D1-D6, and F1-F4) HBV is geographically distributed in a diversified way. In the Amazon basin, genotypes A, D, and F are concentrated, with genotype F considered specific to the Americas with predominance in native populations. Virological aspects such as genotypes, subgenotypes, mutations, and coinfection with hepatitis Delta virus (HDV) are determinants of the complexity of the disease in chronic carriers. To characterize the genotypes and subgenotypes of HBV in indigenous people with chronic HBV and co-infected with HDV analyze epidemiological, sociodemographic, serological, and molecular data of indigenous people living in the cities of Guajara Mirim and Nova Mamore located in the state of Rondônia/ Brazil. All the procedures used in the study followed the terms determined by the National Council of Ethics in Research – CONEP. In this context, the study population consisted of 41 indigenous people of both sexes, over 18 years of age, selected from the reactive results of HBsAg and Total Anti-HBc immunoassays. With the consent of the participants, the biological samples of serum for molecular analysis were collected by the team of the Molecular Virology Laboratory at Fiocruz-RO. The prevalence of HBV found in indigenous people located in the border region between Brazil and Bolivia was 2.8% (168/5908); of these, a total of 41 indigenous people, 27 mono-infected with HBV and 14 coinfected with HDV, were volunteers in the study. It was observed that 49% (20/41) of the participants had a family history of HBV infection and more than half of the population were =or> 40 years old (24/59%). Indigenous males (66% n=41) were more frequent than females (34% n=41). The mean time of HBV infection was 12.6 years (with a minimum of 2 and a maximum of 24 years). A total of 65.9% (27/41) of the Indigenous people were positive for DNA-HBV. Of the positives, 39% (16/41) are mono-infected and 27% (11/41) are co-infected with HDV. In the genotypic characterization, genotypes A, D, and F were observed, with a frequency of 40.7% (11/27) for genotype D (HBV-D), 33.3% (9/27) for genotype F (HBV -F,) and 25.9% (7/27) A (HBV-A); as for the observed subgenotypes, F2, F4, D2, D3, A1, and A2 were found. In addition, an important C69* stop codon mutation associated with the risk of cellular hepatocarcinoma was observed in a single sequence of individuals coinfected with HDV. Thus, there is evidence of genotypic diversity in the population that reveals a predominance of genotype D, which is more specific to the southern region of Brazil. The HBV genotypes and subgenotypes circulating among the Indigenous people of the State of Rondônia demonstrate for the first time the HBV-D genotype with greater frequency among the natives of the region. In conclusion, our findings showed a diversity of HBV genotypes, which is also found in other Brazilian geographic regions. Genomic surveillance in endemic locations for hepatitis B favors preventive public health measures to reduce HBV infection, and consequently HDV in endemic regions for the virus.

6
  • JEANE DO NASCIMENTO MORAES
  • Structural and functional characterization of a Cathepsin D Enzyme Complex and a Bothrops jararacussu phospholipase A2.

  • Leader : LEONARDO DE AZEVEDO CALDERON
  • MEMBRES DE LA BANQUE :
  • ANTONIO COUTINHO NETO
  • LEANDRO SOARES MOREIRA DILL
  • LEONARDO DE AZEVEDO CALDERON
  • NIDIANE DANTAS REIS PRADO
  • SHARON ROSE ARAGAO MACEDO OLIVEIRA
  • Data: 27 oct. 2022
    Ata de defesa assinada:


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  • Cathepsin D (CatD) is a lysosomal proteolytic enzyme expressed in almost all tissues
    and organs. It is a multifunctional enzyme responsible for important proteolytic events for the
    regulation of biological processes such as cell cycle migration and differentiation, tissue
    remodeling, neuronal growth, ovulation and apoptosis. Its overexpression and hypersecretion
    have been correlated with cancer aggressiveness and tumor progression, stimulating cancer cell
    proliferation, fibroblast growth and angiogenesis. Furthermore, some studies report its
    participation in neurodegenerative diseases and inflammatory processes. The search for new
    inhibitors from natural products can be an alternative against the harmful effects of the action
    of this enzyme. For this, we investigated the interaction of CatD with snake venom toxins in an
    attempt to find inhibitory molecules. Interestingly, human CatD shows the ability to bind
    strongly to snake venom phospholipases A2 (svPLA2), forming a stable muti-enzymatic
    complex that maintains the catalytic activity of both CatD and PLA2. In addition, this complex
    remains active even under exposure to the specific inhibitor Pepstatin A. Furthermore, the
    complex formation between CatD and svPLA2 was evidenced by surface plasmon resonance
    (SPR), two-dimensional electrophoresis, enzymatic assays, and extensive molecular docking
    and dynamics techniques. Thus, this study evidences the versatility of human CatD and
    svPLA2, showing that these enzymes can form a fully functional new enzymatic complex.

7
  • ALYNE CUNHA ALVES DIAS
  • Avaliação de diferentes composições de Isca Atraente Açucarada Tóxica (ATSB) e Isca Açucarada Tóxica (TSB) e sua associação com estações de isca como ferramenta para controle de Aedes aegypti (Diptera: Culicidae)

  • Leader : ALEXANDRE DE ALMEIDA E SILVA
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • JOSÉ BENTO PEREIRA LIMA
  • ANTONIO MARQUES PEREIRA JUNIOR
  • CLAUDIA MARIA RÍOS VELÁSQUEZ
  • ROSEMARY APARECIDA ROQUE
  • Data: 5 déc. 2022


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  • The use of sugar baits to deliver insecticides can be an alternative measure for the control of Ae. aegypti, which may include the use of specific devices for its application, i.e., bait stations (EI). The composition of these baits can be quite simple, i.e., sugar solution and insecticide (TSB), or it can also include attractants (ATSB). Although different insecticides and attractants have already been studied, few studies have investigated the bait composition and its relationship with its ingestion by mosquitoes using different models of EIs. That said, the aim of this study was to evaluate the effect of the composition of sugar baits (TSB and ATSB) with ivermectin (IVM) and its use in different bait stations (EI) on Ae. aegypti in the laboratory. Sugar baits with different types (crystal and brown) and concentrations (10%, 50% or 70%) of sugar and IVM (0.312ppm to 1000ppm) containing or not attractants (concentrated juice or guava pulp) were prepared through dilutions simple of stock solutions. The EIs were constructed using bottles, boxes, artificial plants and adapted plant pots. The experiments were carried out in screened cages (containing 20 to 30 mosquitoes) and the baits
    were offered on cotton balls, except for the last experiment which was carried out in a tent, containing 100 mosquitoes and the baits were sprayed in EIs. Engorgement and mortality of males and females of Ae. aegypti was recorded using a stereomicroscope after 6 hours. Sugar type and juice source did not affect the engorgement of ATSBs, which was lower in relation to TSB. Higher concentrations of sucrose (50% and 70%) in baits with 100ppm of IVM were more engorged but did not change the mortality rate of males and females. High concentrations of IVM (500-1000ppm) using 70% sucrose reduced engorgement and, in general, caused mortality above 89%. The use of different concentrations of IVM in baits containing 10% and 70% sucrose to calculate the Lethal Concentrations (CLs) resulted in 28% and 63% higher engorgement in males and females, respectively, in baits containing 70% sucrose. compared to those containing 10% sucrose in ATSBs. Using TSBs, regardless of sucrose concentration, the engorgement rate was greater than 84% for males and females. The mortality rate increased with increasing IVM concentrations in the two baits, regardless of the sucrose concentration evaluated. In addition, the use of 70% sucrose caused a significant reduction in the LC50 of the TSB for females and males, however there was a significant increase in the LC90 in both baits only for females. Finally, engorgement was higher in the EIs with the baits containing 70% sucrose. Bait sprayed in Resting Boxes were generally more engorged by males and females. In the present study, the use of TSB, 70% sucrose and the Resting Box model bait station resulted in better mosquito engorgement under the experimental conditions used.

2021
Thèses
1
  • FELIPE SOUZA NOGUEIRA LIMA
  • xx

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • GABRIEL EDUARDO MELIM FERREIRA
  • ALEXANDRE DIAS TAVARES COSTA
  • Data: 8 avr. 2021


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  • The hepatitis Delta virus (HDV) causes the most severe form of liver disease among all viral hepatitis, in addition to being considered a globally distributed agent. It has a level of genetic variability that allows it to be organized into 8 genotypes and with different geographical distributions between them. Its earliest report occurred in the 1930s, in South America. On this continent, genotype 3 (HDV-3) appears to be exclusive and the most frequently isolated. It is associated with the most severe form of hepatitis Delta, in contrast when the infection manifests itself in indigenous populations, where it can present asymptomatically and with greater sensitivity to treatment. The phylogenetic relationship of HDV-3 with the other genotypes is the most distant, having a direct evolutionary link with the last ancestor common to all HDV genotypes. Such information supports a hypothesis that the geographic origin of HDV is in South America and may be associated with indigenous populations. Based on this information, the study aimed to describe the evolutionary dynamics of HDV and its evolutionary history in the South American continent, analyzing genomic portions of viral strains isolated from patients from indigenous and non-indigenous populations, together with sequences already deposited in a genomics bank containing representativeness of all eight genotypes. The analyzes showed that the most recent common ancestor of HDV-3 was dated in 1940 and indicated that the dispersion may have started in Brazil, spreading to Venezuela, Peru and Colombia later. There was an exponential increase in the effective number of infections between the 1940s and 1980s, years after the first report of the presence of HDV on the continent during the outbreak of Labrea Black Fever, suggesting that the virus continued to spread and increase the number of cases decades after the first reports. In the new millennium, the analysis showed a decrease in the population dynamics of HDV-3, probably due to the implantation of the vaccine against its auxiliary virus, the hepatitis B virus, and serological screening methods implemented in blood banks. The analysis of the temporal phylogeny and dating of the last ancestor common to all HDV genotypes allowed us to observe that it circulated between the nineteenth and twentieth centuries, more closely to 1911. When considering the conclusions obtained with genotype 3 and its position in the posterior and cladistic distribution in the reconstructed phylogeny of HDV (the only branch directly connected to the root of the tree), it can be assumed that this ancestor was circulating in South America. between different populations from different locations in the country and the world who had not previously had contact, including here the initial contact with native indigenous populations. Such foundations and associations generated a possibility that the Amazon of the mid-19th and 20th centuries hosted the first focus of HDV dissemination with consequent subsequent dissemination across the globe.

2
  • TÁRCIO PEIXOTO ROCA
  • Genomic analysis of Hepatitis B Virus variants in chronic carriers of the Specialized Viral Hepatitis Outpatient Clinic of Porto Velho, Rondônia

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • LIVIA MELO VILLAR
  • SORAYA DOS SANTOS PEREIRA
  • Data: 8 avr. 2021


  • Afficher le Résumé
  • O genoma do HBV é considerado o menor entre os vírus DNA, possuindo tamanho aproximado de 3.2kb e 4 regiões de leitura aberta. O genoma possui diferenças nucleotídicas suficientes para classificação do HBV em 10 genótipos principais (A, B, C, D, E, F, H, I e J) e mais de 30 subgenótipos. O surgimento de mutações e variantes virais tem sido motivo de bastante discussão na literatura em relação a probabilidade de algumas dessas cepas ocasionarem escape ao sistema imunológico do hospedeiro, potencialidade de causar evolução à doença hepática de forma mais grave como cirrose e HCC, além do surgimento de variantes resistente ao tratamento. Esta pesquisa tem como objetivo analisar a frequência de mutações e variantes circulantes do vírus da hepatite B em indivíduos portadores crônicos do Ambulatório Especializado de Hepatites de Porto Velho, Rondônia. Trata-se de um estudo transversal com componente descritivo e analítico. O recrutamento de pacientes foi realizado por conveniência de acordo com os critérios de inclusão e exclusão. Foi adotada a técnica de PCR convencional para a amplificação do genoma completo do HBV, sendo que um total de 4 diferentes finais são originados, os quais dão cobertura de todo o genoma. A genotipagem foi determinada por meio da construção de uma árvore filogenética. A identificação de mutações nos genes (pré-S/S, P, X e pré-C/C) foi realizada por meio da construção dataset’s correspondentes a cada gene. De todas as amostras amplificadas, apenas 34 foram sequenciadas atém o presente momento em pelo menos 1 dos 4 fragmentos do genoma. Os achados do estudo mostram a presença dos subgenótipos A1 (17/34, 50%), D3 (7/34, 20,6%), F2 (5/34, 14,7%), D2 (2/34, 5,9%), A2 (1/34, 2,9%), D1 (1/34, 2,9%) e F4 (1/34, 2,9%). As análises no gene S mostraram a presença das mutações sG130S (2/28, 7,1%), Y100C (1/28, 3,44%), sL109M (1/28, 3,6%), sP120T (1/28, 3,6%), sG130N (1/28, 3,6%), sM133T (1/28, 3,6%), S/T140I (1/28, 3,6%) e sE164G (1/28, 3,6%). Um total de 6 amostras (6/30, 20%) apresentaram alguma deleção na região Pré-S2. Duas amostras continham, respectivamente, as alterações rtQ215H (1/28, 3,6%) e rtM250I (1/28, 3,6%). No gene X, foram identificadas as alterações A1762T/G1764A (4/5, 80%), T1653C (2/5, 40%), T1753C (2/5, 40%), G1613A (1/5, 20%). Os resultados das análises na região pré-C/C mostraram a presença das substituições G1896A (2/7, 28,6%), P5L (1/7, 14,3%) e A131V (1/7, 14,3%). Os achados das variantes genotípicas observadas corroboram com resultados de pesquisas na região. Apesar da relação das mutações no gene S com escape imunológico, não foi identificado nenhum paciente HBsAg negativo. Resultados de pesquisas não relacionam mutações de resistência identificadas ao comprometimento da eficácia da atual terapia preconizada pelo Ministério da Saúde. As mutações nos genes pre-C/C e X podem ter potencial de avanço de doença hepática, no entanto, uma análise experimental mais abrangente é necessária. As comparações de frequências de genótipos e deleções pré-S2 identificadas neste estudo ao estágio da doença hepática dos indivíduos apresentaram valor de p não significativo.

3
  • LUIZ HENRIQUE MACIEL FEITOZA
  • Hematophagic activity of Culicoides paraensis (Diptera: Ceratopogonidae) by human landing catches and natural infection analysis by Oropouche Virus in the urban area of Porto Velho, Rondônia.


  • Leader : GENIMAR REBOUÇAS JULIÃO
  • MEMBRES DE LA BANQUE :
  • GENIMAR REBOUÇAS JULIÃO
  • JANSEN FERNANDES MEDEIROS
  • FRANCINALDO SOARES SILVA
  • Data: 13 oct. 2021


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  • The insects of the genus Culicoides are dipterans of the family Ceratopogonidae. Some species have medical and veterinary importance and C. paraensis is considered a vector of the Oropouche Virus (OROV) in the urban cycle of the disease. It is a species highly adapted to urban and periurban environments and has anthropophilic behavior, being found in high density in urban centers of the Brazilian Amazon. The studies of infection and experimental transmission have shown that C. paraensis is capable of infecting and transmitting OROV in areas with arbovirus outbreaks. Due to the great abundance of insects of the genus Culicoides in Porto Velho, mainly of C. paraensis, and with the recent emergence and reemergence of OROV in Brazil, it is necessary to investigate entomological indexes of biting midges and the dynamics of transmission by this vector. The objective of this dissertation was to evaluate the importance of C. paraensis as a potential vector of Oropouche Virus in the urban area of Porto Velho through molecular investigation for natural infection and study of vector behavior by analyzing hematophagic activity and its abundance as a function of meteorological parameters. The captures occurred in two localities in the urban area of Porto Velho by means of outdoor human landing catches (HLC). Samplings occurred during three days from 6:00 am to 8:00 pm, in July, August (dry season) and December 2019 and in January 2020 (rainy season). Generalized Linear Mixed Models were performed to analyze the response of insect hematophagic behavior to seasons, daily hour and meteorological factors (temperature and relative humidity). Total RNA extracted from insects were subject to RT-qPCR, for the detection of viral RNA using the S segment as the OROV target region. Overall, 6,079 individuals were captured which were taxonomically identified as C. paraensis. In the Juscelino Kubitschek neighborhood, 2,725 specimens (44.8%) were captured, while in Nova Esperança there were 3,354 insects (55.2%). During the dry season, 1,488 individuals (24.5%) were sampled, and 4,591 (75.5%) in the rainy season. Considering total number of insects regardless of month and neighborhood, the highest activity peak occurred between 4:00 pm and 6:00 pm. In December, another peak was observed between 11:00 am and 1:00 pm, while in the other months the peak trend was maintained in the range of 4:00 pm to 6:00 pm. The hourly number of biting midges remained more uniform and with fewer oscillations (peaks) during the dry season. All independent variables had significant influence on the biting midges, with rainy season, temperature between 30°C and 32°C and relative humidity between 75% and 85% as predictor parameters for higher average insect capture. The results confirm that this biting midge specie have diurnal activity and are attracted to humans for blood feeding: a single collector captured 220 individuals from 5:00 pm to 6:00 pm. The activity peak variation between study areas suggests that physical and meteorological factors of microenvironments may be influencing the species behavior. None RNA samples had amplification for target OROV sequences, which can be explained by the possible noncirculation of OROV in the human population in the urban area of Porto Velho, C. paraensis as a secondary or non-vector vector, and low infection rate among insects. These hypotheses, together with the probable underreporting of human cases of OROV in the Amazon region, reinforce the need for studies on the species bionomy and molecular investigation to explain the role of Culicoides paraensis as a vector of this arbovirus.

4
  • ORTÊNCIA DE OLIVEIRA SOUSA
  • x

  • Leader : SORAYA DOS SANTOS PEREIRA
  • MEMBRES DE LA BANQUE :
  • SORAYA DOS SANTOS PEREIRA
  • STELLA REGINA ZAMUNER
  • LIVIA CARICIO MARTINS
  • Data: 6 déc. 2021


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  • Bioactive molecules, such as peptides, proteins and enzymes are found in the biodiversity showing therapeutic potential in neglected diseases. Snake venom and its fractions are of great interest due to its virucidal potential demonstrated in in vitro studies. The Dengue Virus (DENV) is the most important arbovirus that infect humans - with 400 million cases every year, and with an increasing number of severe cases with dengue hemorrhagic fever or dengue shock syndrome. Although there is no specific medication to treat dengue infection, snake venoms may represent a potential source of antiviral activity. In this perspective, the present study aims to evaluate the effects of different toxins isolated from the Bothrops diporus snake venom on DENV. For the study, cell cultures of the C6/36 and VERO lineages were established for viral cultivation and propagation, from the isolation of DENV from the serum of patients previously characterized by molecular biology. The detection of virus serotype maintained in culture was performed by RT-qPCR using specific oligonucleotides, and viral titration performed by flow cytometry, with confirmation of cell infection by indirect immunofluorescence and the performance of the kinetics of viral infection of DENV serotype 1 (DENV1). The results obtained for viability tests in VERO cells of the different toxins tested for standardization demonstrated that the Crotoxin in 1h and 24h showed viability greater than ± 60% and when incubated for 5 days, the concentration of 50 µg / mL affected 50% of cell viability. The BthTX-II incubated for 4 days, showed viability greater than ± 50%. While PLA2 BthTX-II from Bothrops jararacussu incubated for four days showed viability greater than ± 50%. When tested the B. diporus venom and toxins – the target biomolecules of this study – on the cell cytotoxic assay, the venom (50µg/mL) showed CC50; and PLA2-Asp (12.5 - 50 µg / mL) affected cell viability in the percentage of ± 50 - 65% respectively. PLA2-Lys has been shown to affect 50% of cells at a concentration of 50 µg/mL. The viral serotypes 1 and 3 were detected after the 2nd viral culture of RT-qPCR. Among the serotypes evaluated, when performing DENV1 replication kinetics in C6/36, the virus showed a gradual increase in viral particles which were stabilized from the 5th to 6th day of incubation being detected by indirect immunofluorescence. In conclusion, after propagation stages it was possible to identify and detect by molecular and cellular methods only DENV1. In cytotoxicity analysis, which is one of the first tests of a drug candidate and performed in mammalian cells, the CC50% presented PLA2s ranged between 25-50 µg/mL. The preliminary results obtained allows the continuation of the study, which consists of evaluating the antiviral activity of snake toxins and venoms. Since PLA2s showed antiviral potential, more researches on the same class of biomolecules contributes to a better understanding of the mechanism of action.

5
  • MAICON ALEANDRO DA SILVA GOMES
  • x

  • Leader : NAJLA BENEVIDES MATOS
  • MEMBRES DE LA BANQUE :
  • CHRISTIAN COLLINS KUEHN
  • MELISE CHAVES SILVEIRA
  • NAJLA BENEVIDES MATOS
  • Data: 17 déc. 2021


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  • Acinetobacter spp. are coccobacillary bacteria, Gram-negatives, aerobics, nonfermenting, ubiquitous that stand out for being opportunistic pathogens in hospitalized patients due to their great capacity to develop on abiotic surfaces, to resist desiccation and to be resistant to the action of multiple antibiotics. Of this genus, Acinetobacter baumannii stands out, which in 2017 was classified by the World Health Organization as a critical priority for multidrug resistance, thus representing one of the greatest threats to human life. Resistance to beta-lactams has been reported in association with resistance genes that, with each passing day, increase and are spread inter and intraspecies. Therefore, this work aims to identify and characterize the different species of Acinetobacter spp. isolated from clinical samples of patients, health workers and hospital structures of intensive care units of hospitals in the Porto Velho region, as well as their phenotypic and molecular profiles of resistance to beta-lactams. 201 Acinetobacter spp. isolates were identified, with Acinetobacter baumannii being the most incident species among the nine identified. The isolates are more sensitive to the action of polymyxin B, however there was greater resistance to the classes of monobactam, cephalosporins and fluroquinolones, determining a scenario that 53.3% of the isolates were classified as multiresistant, of which 77.7% can be extensively resistant. In vitro, non-betalactam antibiotics had 21.08% more chances of being more effective. 83% of the isolates were negative for extended sputum beta-lactamases, a condition statistically associated with multiresistant isolates. 90.6% of the isolates were biofilm producers, especially those from patients. The blaOXA-23 gene was the most amplified betalactamase in the isolates, followed by the oxacilinases blaOXA-24 and blaOXA-58. blaNDM was the most amplified metallobetalactamase gene, and 92.86% of these genes were identified as coexisting with other betalactamase genes. It is concluded that surveillance should be continuous, suggesting new studies aiming at identifying other genes encoding beta-lactamases and or other inactivating enzymes for antibiotic drugs, as well genes that induce the production of efflux pumps, the modification of membrane permeability or porins channels.

6
  • CLEIDIANE DOS SANTOS ORSSATTO
  • xx

  • Leader : CHRISTIAN COLLINS KUEHN
  • MEMBRES DE LA BANQUE :
  • CHRISTIAN COLLINS KUEHN
  • JORGE JAVIER ALFONSO RUIZ DIAZ
  • SULAMITA DA SILVA SETUBAL
  • Data: 20 déc. 2021


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  • The growing development of antimicrobial resistance, and the decrease in the supply of anti-infective drugs, arouse the need to look for therapeutic alternatives that are effective and safe. Therefore, as a strategy, antimicrobial peptides have numerous advantages, from less likely to induce microbial resistance, potent and fast microbicidal action at micromolar concentrations, synergistic capacity, in addition to immunomodulating properties. Among those, the vast amount of peptides from the skin of anurans stand out, such as Ocellatin-KN, constructed from Ocellatin-K1, isolated from the secretion of the skin of Leptodactylus knudseni. In this frame, the objective of this work was to evaluate in vitro the antimicrobial profile of OKN against ATCC strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and ATCC strain of the yeast Candida albicans, in addition to the evaluation of the cytotoxic and immunomodulatory characteristics related to the production of ROS, IL-6 and OKN phagocytosis stimulation on murine peritoneal macrophages. The physical-chemical and structural characteristics of OKN were determined in silico, using bioinformatics tools. The antimicrobial and biofilm inhibition (MIC and MBIC) potential of OKN was performed by the broth microdilution method, at concentrations from 500 to 3.9 μg/mL. With the same concentrations as related, the cytotoxicity of the peptide was tested against mouse peritoneal macrophages by the MTT method, with incubations of 24 and 48 hours. An assay for the production of ROS was carried out based on a fluorescence reaction, with concentrations of OKN from 500 to 31.2 μg/mL. The supernatant (from the cytotoxicity assay) produced in 6 hours was used to measure Interleukin 6 using the immunoenzymatic method, with concentrations of OKN from 62.5 to 7.8 μg/mL. The phagocytosis assay was conducted using opsonized zymosan particles using OKN concentrations of 125, 62 and 31 μg/ml. The results were analyzed using the GraphPad Prism software version 6.0, performing the analysis of variance (One-Way ANOVA) with the application of Tukey's post-test. It was observed that OKN has mild activity against the bacteria tested, with a MIC of 125 μg/mL for the two gram-negative strains (E. coli and P. aeruginosa) and 15.6 μg/mL for S. aureus; and no inhibitory effect on C. albicans. Biofilm formation of E. coli and P. aeruginosa was discretely inhibited at the highest concentrations (500 and 250 μg/mL) and noticeably inhibited for S. aureus and C. albicans at all concentrations (500 to 3.9 μg/mL). On murine peritoneal macrophages, OKN was cytotoxic at concentrations equal to and greater than 125 μg/mL, and did not stimulate the production of ROS even at the highest concentrations tested, however, an increase in the production of the cytokine IL-6 was observed in the concentration of 62.5 μg/mL, in addition to increasing the rate of phagocytosis by macrophages at all concentrations evaluated. These findings suggest that OKN has mild antimicrobial activity, antibiofilm potential and likely immunostimulating activity on murine macrophages

Thèses
1
  • MINELLY AZEVEDO DA SILVA
  • In silico investigations and in vitro activity of a natural amide and semisynthetic analogs against Leishmania (Viannia) braziliensis.

  • Leader : CHRISTIAN COLLINS KUEHN
  • MEMBRES DE LA BANQUE :
  • CHRISTIAN COLLINS KUEHN
  • FERNANDO BERTON ZANCHI
  • IZALTINA SILVA JARDIM CAVALLI
  • AMANDA FEITOSA CIDADE
  • GEISA PAULINO CAPRINI EVARISTO
  • Data: 26 août 2021


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  • Leishmaniasis is considered a neglected disease, against which the therapeutic options are limited. The disease does not constitute an attractive market for the pharmaceutical industry. Thus, the efforts in the search for biologically active substances are hindered by this lack of interest. Within this context, the study aimed at assessing the cytotoxicity, the hemolytic, and the antileishmanial activity of the natural compound Piplartine (1a) and a series of five synthetic analogs (1b, 1g, 1k, 1m and 14f)  against Leishmania (V) braziliensis, a species that causes cutaneous leishmaniasis. The compounds with promising (ICA50 ≤ 10 µM) antileishmanial activity were assessed for their action mechanism against promastigotes, as well as their enzyme-inhibition activity against Trypanothione reductase, responsible for the parasite’s redox balance. Among the evaluated compounds, Piplartine (1a) and 1m (synthetic derivative) were the most potente compounds against promastigote forms, with IC50 values of 8.58 and 11.25 µM, respectively; for amastigotes, the ICA50 values were 1.46 and 16.7 µM, respectively. The selectivity indexes (SI) estimated for 1a and 1m concerning the cytotoxicity data of THP-1 cells were 20.21 and 3.9, respectively. None of the compounds was hemolytic at the highest concentration (500 µM). 1b, 1g, and 1k were not found to present toxicity towards any of the cell lines here evaluated at the highest concentration (500 µM). On the other hand, 1m and 14f presented cytotoxicity for J774 (CC50 = 89.5 and 18.5 µM, respectively) and THP-1 cell lines (THP-1 = CC50 65.2 and 251.6 µM, respectively). 1a was the less toxic compound against THP-1 cells. The structural modifications were observed to decrease both the cytotoxicity of the analogs (1b, 1g, 1k, 1m and 14f) and their antileishmanial activity. Results on the action mechanism investigations revealed that 1a increased reactive oxygen species (ROS) levels, and induced loss of cell membrane integrity and caused accumulation of lipid bodies after 24 h of incubation at its lowest inhibitory concentration (IC50), which was not observed for 1m. Based on molecular docking and in vitro studies, we suggest that 1a (piplartine) may inhibit the Trypanothione reductase enzyme, decreasing the parasite’s defense against ROS, which would explain the activity of the compound against both the promastigote and amastigote forms.

2
  • MAURO VALENTINO PALOSCHI
  • BIOGENESIS OF HUMAN NEUTROPHIL PRO-INFLAMMATORY MEDIATORS STIMULATED BY L-AMINO ACID OXIDASE OF Calloselasma rhodostoma VENOM

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • GUSTAVO BATISTA DE MENEZES
  • JOSÉ ROBERTO MINEO
  • HELDER TAKASHI IMOTO NAKAYA
  • PATRICIA TORRES BOZZA
  • Data: 29 sept. 2021


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  • Snake venom contains compounds that have the potential to be used in bioprospecting in biology and medicine. These proteins, such as L-amino acid oxidases (LAAOs), cause edema, microbicidal activity, cytotoxicity, coagulant and anticoagulant activity, hemorrhagic and pro-inflammatory effects. LAAO isolated from the venom of Calloselasma rhodosthoma (Cr-LAAO) has been shown to be a powerful stimulator of neutrophil activation and inflammatory mediator production. However, the mechanisms underlying Cr-LAAO-induced cell activation are not well understood. Previous research has shown that this enzyme can activate the NADPH oxidase complex and the PKC-  signaling protein, resulting in the production of reactive oxygen species (ROS), as well as stimulate phagocytosis, chemotaxis with the participation of p38 MAPK and PI3K, MPO release, cytokine production (IL-8, IL-6, and TNF-), neutrophil extracellular traps (NETs), and lipid mediators (LTB4 and PGE2). The activation of the cyclooxygenase (COX) pathway can result in the formation of some lipid mediators within lipid droplets (LDs). LDs are cytoplasmic organelles that are highly associated with the inflammatory response. They are found in a variety of cell types and can increase in number and/or size during an infection. Simultaneously, ROS can activate other inflammatory mechanisms such as inflammasomes. NLRP3-type inflammasomes are cytosolic protein complexes that cleave caspase-1, resulting in the proteolytic activation of pro-inflammatory cytokines such as IL-1. Thus, the purpose of this study is to assess the effect of Cr-LAAO on the activation of the NLRP3 inflammasome, as well as the activation of the COX pathway for the production of PGE2 and its involvement in the formation of LDs. The neutrophil transcriptome was examined using the microarray technique, and it was discovered that Cr-LAAO plays a role in upregulating the expression of genes involved in the NADPH oxidase complex and inflammasomes, as well as genes involved in lipid signaling and metabolism. Immunofluorescence assays for NLRP3 revealed protein accumulation and the formation of punctas in the cytosol, indicating that this complex is activated. Furthermore, protein expression analysis in the presence and/or absence of Apocynin, an inhibitor of NADPH oxidase, revealed that when ROS are inhibited, the expression of proteins that comprise the NLRP3 inflammasome is reduced. The release of IL-1β was also detected, and the pharmacological inhibition of NLRP3, caspase 1 and ROS reduced the levels of this released cytokine. Some of the genes positively regulated in the microarray belong to the phospholipase A2 family, specifically cytosolic phospholipases A2- (cPLA2-); and enzymes involved in the synthesis of PGE2, COX-2, and prostaglandin E synthase (PTGES). In addition, the genes perilipins 2 and 3 (PLIN 2 and 3) and diacylglycerol acyltransferase 1 (DGAT1), which are involved in the formation of LDs, were up-regulated. In neutrophils, Cr-LAAO stimulated increased cPLA2-phosphorylation, LD biogenesis, and PGE2 synthesis. cPLA2- (CAY10650) and DGAT-1 (A922500) inhibitors inhibited LD formation and PGE2 secretion. Finally, this is the first study to look at the effects of Cr-LAAO on the regulation of metabolism and lipid signaling in human neutrophils, as well as its ability to stimulate the activation of the NLRP3 inflammasome complex via ROS production

3
  • GUILHERME MATOS PASSARINI
  • In vitro, ex vivo and in silico studies of a triterpene against Plasmodium spp

  • Leader : CAROLINA BIONI GARCIA TELES
  • MEMBRES DE LA BANQUE :
  • CAROLINA BIONI GARCIA TELES
  • LUIS ANDRE MORAIS MARIÚBA
  • LEANDRO SOARES MOREIRA DILL
  • ERNESTO RAÚL CAFFARENA
  • GEISA PAULINO CAPRINI EVARISTO
  • Data: 25 nov. 2021


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  • Malaria is responsible for 200,000 deaths each year on average. Currently, the combination of artemisinin derivatives (ACT) is used as the first-choice treatment against the disease. However, the resistance of ACT-resistant strains motivates alternative sources of compounds with antiplasmodial activity. Thus, the present study aimed to investigate the in vitro, in silico and ex vivo antiplasmodial activity of a trioxidized semi-synthetic triterpene, called CL-1, as well as its cytotoxicity. The study also aimed to analyze the ability of the compound to inhibit the invasion of the merozoites in human red blood cells. Antiplasmodial tests were performed on human erythrocytes infected with the W2 strain of Plasmodium falciparum and evaluated by the Sybr Green fluorimetric technique. Cytotoxicity was performed on HepG2 and VERO cells, and was assessed using MTT assays. Studies of hemolytic action were also carried out, in order to investigate whether the action of the compound on the parasite is direct or indirect; and ex vivo studies performed on patient samples against circulating strains of P. falciparum and P. vivax. Additionally, in silico studies were carried out with the triterpene compound CL-1: molecular docking analysis against the enzyme trans-2-ACP-enoyl-reductase (PfENR) from P. falciparum; and virtual analysis of physicochemical properties. Preliminary results showed that CL-1 has an inhibition value of 50% of the parasite population (IC50) of 19.8 µM against P. falciparum (W2 strain) and a cytotoxic concentration value for 50% of the cell population (CC50) higher than 500 µM for HepG2 and VERO cell lines. Ex vivo experiments demonstrated that CL-1 has IC50 values ranging from 0.1 to 99 µM for the circulating strains of P. falciparum and P. vivax. The compound also showed no hemolytic action against human red blood cells and was not shown to impede the ability to block invasion into the red blood cells. CL-1 also demonstrated in silico interaction with PfENR, with an estimated ∆G of -6.58 kcal/mol, in addition to complying with most of the physicochemical parameters established by Lipinski and Veber. So far, the results indicate that the compound CL-1 has great potential in antimalarial drug development.

4
  • GLAUCILENE DA SILVA COSTA
  • Diversidade Genética e Taxonomia Integrada de Flebotomíneos (Diptera: Psychodidae) Amazônicos

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • JANSEN FERNANDES MEDEIROS
  • REGINALDO PEÇANHA BRAZIL
  • PALOMA HELENA FERNANDES SHIMABUKURO
  • EUNICE GALATI
  • ANDREA FERNANDES BRILHANTE
  • Data: 16 déc. 2021


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  • Sand flies are important insects in public health that act as vectors of Leishmania, that cause leishmaniasis. In Rondônia State, studies about sand flies have been carried out since the 1960s which knowledge of local fauna is important for identification of vectors and understanding of the dynamics of disease transmission. Currently, sand fly identification is based on morphology of adults, which can be problematic when species are morphologically similar. The diversity of these insects and occurrence of cryptic species in Rondônia makes it difficult the identification based only on morphological characters, then approaches that help the classical taxonomy can improve the accuracy of the correct species identification. Therefore, this study aimed to implement the use of DNA Barcoding in Amazonian sand flies to optimize the species identification and investigate the existence of cryptic species, associating this approach to classical taxonomy in the description of fauna of the region. For this study, specimens from other projects carried out by Fiocruz Entomology Laboratory were used, in addition to additional collections carried out in four municipalities of Rondônia. A toral of 652 specimens belonging to 69 morphospecies were morphologically identified, then legs or thorax were removed, and their genomic DNA were extracted, and the cytochrome c oxidase subunit I (coI) fragment was amplified and sequenced. Sequences were analyzed by best-match and best close match similarity criteria and six different delimitation methods of single-locus (ABGD, RESL, TCS, GMYC, PTP and mPTP) were used to infer operational taxonomic units (OTUs). Sequences data of coI region produced in this study was evaluated with those previously published, and the database was analyzed using ABGD and TCS species delimitation methods. The gene coI proved to be useful for identification of approximately 80% of analyzed species from Rondônia, not being effective in separation in some species of the genus Evandromyia, Nyssomyia, Trichophoromyia and Trichopygomyia. The analyzes showed the presence of cryptic diversity, in at least four analyzed algorithms, for the species: Bichromomyia flaviscutellata, Evandromyia bacula, Evandromyia tarapacaensis, Evandromyia wilsoni, Nyssomyia fraihai, Psychodopygus carrerai, Psychodopygus davisi and Trichophoromyia ubiquitalis. Also was possible to establish the association between males and their respective females, which have isomorphic process between species. The approach also enabled description of Pintomyia fiocruzi and Psathyromyia pradobarrientosi females. Sequence analyzes of specimens from other locations and Rondônia demonstrate the importance of using a robust database to improve accuracy in delimitation of sand fly species. When barcodes of closely related species or from different geographic regions were added, changes were observed in delimitation of some species, showing events such as a much greater cryptic diversity or grouping closely related species. The results presented reinforce the need for molecular identification as a complement to morphological identification, demonstrating the importance of using this approach to reveal the cryptic diversity of some sand fly species.

2020
Thèses
1
  • LEANDRO DO NASCIMENTO MARTINEZ

  • In vitro evaluation of synthetic compounds derived from Bi-triazoles against sexual and asexual forms of P. falciparum

  • Leader : CAROLINA BIONI GARCIA TELES
  • MEMBRES DE LA BANQUE :
  • CAROLINA BIONI GARCIA TELES
  • ANDREIMAR MARTINS SOARES
  • DHELIO BATISTA PEREIRA
  • Data: 16 mars 2020


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  • ABSTRACT

     

    Considered one of the oldest diseases of mankind, the malaria remains a serious public health problem. Currently, five species of Plasmodium are described to cause malaria in humans and the transmission occurs mainly during the blood repast of infected female of the genus Anopheles spp. Severe malaria caused by Plasmodium falciparum is characterized by the severe clinical features that affects organs and vital systems of the organism. In addition, there are reports of resistance of P. falciparum to some reference drugs. Faced with this and other aggravating factors, the malaria continues to cause the death of more than 400,000 people annually and more than 200 million new cases are reported worldwide. Thus, the development of new drugs for the treatment of that disease is becoming increasingly necessary. In this context, bi-triazoles (targets of this study) are classes of substances that have diverse biological activities and have shown to be promising in the development of new prototypes to combat malaria. The objective of the present study is to evaluate the in vitro antimalarial activity of four compounds from bi-triazole family against P. falciparum. For the bioassays the strain W2 (CQ-Chloroquine resistant) and NF54 (CQ-Chloroquine sensitive) were used. For the IC50 evaluation the Sybr Green I method was used. The cytotoxicity assay assessed by means of the colorimetric assay MTT (3 - ([(4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium]) using the HepG2 cell line, then the selectivity index (IS) of each test compound was calculated. In parallel, the hemolysis test was performed and the blocking activity of the exflagelation of the compounds was also verified. Based on the results obtained for the four compounds, it was possible to observe the potency of compound 10RJ (1-(5-(Trifluoromethyl) -4H-1,2,4-triazol-3-yl)-1H-1,2,3-triazol-4-yl) methyl acetate, with inhibition of the parasite in 0.45 μM IC 50. The compounds showed no cytotoxic activity against HepG2 (CC50 ˃ 500 μM), nor exacerbated haemolytic rates. The selectivity index for compound 10RJ was 1.111. For the sexual forms, the inhibition of exflagelation was 79.2%. The data will be complemented with compound combination analysis. The results of this study may contribute to increase the database on the profile and action of bi-triazole derivatives with the antimalarial action, and to choose new promising alternatives for the treatment of this disease.

2
  • FLAVIA GEOVANA FONTINELES RIOS
  • DETECTION OF ARBOVIRUS IN MOSQUITOES (DIPTERA: CULICIDAE) IN THE URBAN AREA OF PORTO VELHO, RONDÔNIA.

  • Leader : GENIMAR REBOUÇAS JULIÃO
  • MEMBRES DE LA BANQUE :
  • GENIMAR REBOUÇAS JULIÃO
  • NAJLA BENEVIDES MATOS
  • MICHELLE DE OLIVEIRA E SILVA
  • Data: 30 mars 2020


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  • Os mosquitoes have a worldwide distribution, being present in urban, rural and forest environments. Urbanization without planning favors the proliferation and survival of mosquito vectors and diseases in cities. In Brazil, the species of urban mosquitoes that stand out are Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. The three species are associated with the transmission of several arboviruses, such as the Dengue, Zika and Chikungunya and Wuchereria bancrofti viruses (etiological agent of lymphatic filariasis) for the latter species. The general objective of the present work was to verify the abundance of the three main species of mosquitoes and to evaluate the possible occurrence of arboviruses in their populations, in the urban area of Porto Velho, Rondônia. Initially, a preliminary study was carried out in the Tancredo Neves neighborhood with household collections, with the purpose of adapting field and laboratory techniques, and subsequently a study was carried out in 27 residences distributed in nine neighborhoods in intra and peridomestic environments. Two collection techniques were used: ovitrampa (without reed, only for larvae collection) and electric aspiration for the capture of adults lasting 15 minutes. The adults, generated in the laboratory from the larvae, were used to verify the vertical transmission of DENV, CHIKV and ZIKV. The specimens captured by the electric aspiration technique had, in addition to the body, saliva collected on FTA® cards for analysis of the presence of these viruses. The samples were submitted to the RNA extraction process, followed by RT-qPCR in real time. The positive pools were also submitted to a semi-nested PCR protocol and subsequently to capillary sequencing. The species abundance data were analyzed in the Free Platform R and the estimate of infection by virus and by species was calculated by the Minimum Infection Rate (MIR) and Maximum Likelihood (MLE). In the preliminary study, 1,701 mosquitoes were collected, of which 1,332 were used for virus detection, resulting in 76 pools divided between: Culex quinquefasciatus (57), Aedes aegypti (18) and Aedes spp. (1), obtaining two positive pools for ZIKV, resulting in an MIR of 1.50 and 1.51 of MLE. Subsequently, a total of 2,342 mosquitoes were obtained in the nine sampled neighborhoods, distributed in five species, being Cx. Quinquefasciatus, Ae. aegypti and Ae. albopictus the most abundant, constituting 272 pools of which one was positive for DENV (MIR and MLE: 2.58). In addition, it was possible to detect DENV-4 from a sample of saliva collected on an FTA card, which belonged to a female of the Ae species. aegypti. The sequences of the positive samples were identified with DENV-4 genotype II. This study demonstrates the first record of DENV and ZIKV transmission in urban mosquitoes in Rondônia, as well as showing the first occurrence of vertical / venereal transmission of DENV-4 and ZIKV in male mosquitoes of the species Ae. aegypti and Cx. quinquefasciatus, respectively.

3
  • ALEX AUGUSTO FERREIRA E FERREIRA
  • TREATMENT OF SNAKE POISONING: THERAPIES SUPPORTING CONVENTIONAL SEROTHERAPY USING PHOTOBIOMODULATION (LED) AND DEXAMETASONE

  • Leader : JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • MEMBRES DE LA BANQUE :
  • JULIANA PAVAN ZULIANI TRENCH DE SOUZA
  • SORAYA DOS SANTOS PEREIRA
  • MARCOS ROBERTO DE MATTOS FONTES
  • Data: 15 avr. 2020
    Ata de defesa assinada:


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  • Snakebite accidents are a serious and complex public health problem affecting mainly the tropical, subtropical areas of developing countries. Due to its magnitude, ophidism has been reinserted in the World Health Organization's list of Neglected Tropical Diseases. Worldwide, reported cases annually reach 2.1 million, of which 81 to 138,000 die and another 300,000 develop permanent sequelae. In Brazil, the annual average reaches 27,200 cases and in the North region this average appears in fourth place. Among the four snake genera of medical interest, the Bothrops genus is the most important, as it is responsible for about 90% of snakebites. Among the snake species of medical interest, Bothrops jararacussu and Bothrops atrox, found in the south, southeast and north, respectively, have distinct characteristics, among them the composition of the venom itself. This difference makes the clinical aspects presented by the victims of accidents with these snakes also have particularities. Treatment with ophidic serum is effective for systemic effects and ineffective against local effects. Thus, the objective of this study was to evaluate the photobiomodulation treatment with LED and/or dexamethasone associated with conventional serum therapy to treat local damage caused by envenoming by these two snake species. For this, the experimental envenoming was conducted in gastrocnemius muscle of male Swiss mice of mass between 18 and 22 grams (divided into groups of 5 animals) by intramuscular inoculation of 25 μg of B. jararacussu venom and 50 μg of B. atrox venom. After 30 minutes, the proposed treatments were administered alone or in combination. After 3 hours, blood and muscle samples were collected for myotoxicity, cytotoxicity, histological analysis and IL-1β assay. Results reaffirmed that serum therapy is not effective in treating local damage and demonstrated that LED photobiomodulation alone was able to decrease the leukocyte infiltrate in the inoculated muscle, as well as hemorrhage and myotoxicity. Dexamethasone treatment then showed good results in inhibiting myotoxicity against B. jararacussu venom and proved to be an excellent resource for the treatment of the inflammatory process against both venoms. It was concluded that the combination of serum therapy, LED and dexamethasone was very promising for the treatment of snakebites caused by the two species in question, as it will provide efficacy not only to systemic damage, but also to local damage, thus avoiding disfigurement of the affected limb.

4
  • SUYANE DA COSTA OLIVEIRA

  • Title: DEVELOPING AND STANDARDIZING A ONE-STEP REAL TIME PCR TEST FOR DELTA VIRUS (HDV)

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • SORAYA DOS SANTOS PEREIRA
  • JUAN MIGUEL VILLALOBOS SALCEDO
  • RITA DE CÁSSIA PONTELLO RAMPAZZO
  • Data: 29 avr. 2020
    Ata de defesa assinada:


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  • Hepatitis Delta Virus (HDV) is a defective virus that needs the Hepatitis B Virus (HBV) envelope to complete its infectious process. Infection with this virus is associated with more severe liver disease compared to HBV monoinfection. Chronic patients with hepatitis delta are more likely to progress to fibrosis, cirrhosis, cellular hepatocarcinoma, and liver failure. Its still limited diagnosis, carried out by detection of Anti-HDV in HBV serum, only allows detection of viral infection. Molecular techniques such as real-time PCR have sensitivity and specificity for accurate diagnosis, follow-up of the natural course of infection, and monitoring response to treatment; however there are no internationally accepted standardized assays yet. This proposal aims to meet this demand by developing a real time PCR assay for HDV detection and quantification. Filling the gap in the developed in house tests, this test will use the One-Step technique and two internal controls will be inserted, aiming to produce a test of high precision, sensitivity, specificity and reproducibility, characterizing it as a tool for fast, reliable and useful diagnosis. mainly in areas of greater endemicity, such as the Western Amazon region.

5
  • ADRIELE NUNES RODRIGUES SILVA
  • Fauna, molecular detection of Leishmania (Kinetoplastida: Trypanosomatidae) and food preference of sandflies (Diptera: Psychodidae) in districts from the municipality of Porto Velho, Rondônia, Brazil

  • Leader : JANSEN FERNANDES MEDEIROS
  • MEMBRES DE LA BANQUE :
  • ANDRELISSE ARRUDA
  • JANSEN FERNANDES MEDEIROS
  • SERGIO DE ALMEIDA BASANO
  • Data: 25 mai 2020


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  • Sandflies are small insects that feed on plant sap, only females perform hematophagy. This habit allows ingestion and transmission of pathogens, including protozoa of the genus Leishmania. Soon, Some species are of medical importance. In Rondônia, already 135 species of sandflies were recorded, including vectors and species with transmission potential. Therefore, the purpose of this paper is to understand aspects diversity, natural infection and food source of sand flies in the municipality of Porto Velho. The study was conducted in the following districts of Porto Old Man: Nova Mutum Paraná, Bandeirantes Union, Vista Alegre do Abunã and Nova California. Sand flies are being collected using light traps HP, exposed in the forest, edge and peridomicile ecotopes. After screening and taxonomic identification, the thorax and abdomen of engorged females and females are for DNA extraction and PCR directed to the kDNA, hsp70 and Cytb genes. To date, 1,335 specimens have been identified, distributed in 51 species and 14 genres. Among the most abundant species, Psychodopygus davisi, Trichophoromyia auraensis, Nyssomyia antunesi, Psychodopygus hirsutus hirsutus, Trichophoromyia ubiquitalis, Psychodopygus carrerai carrerai, and Psychodopygus complexus have already been incriminated or are considered potential vectors. Until the At this time, the district of New California had the largest abundance (1,033 individuals) and wealth (36 species). Forest ecotopes presented the largest abundance (1,133 individuals) and wealth (46 species). In the peridomiciliaries, even With low abundance (39 individuals), the richness was 15 species. This corroborates with previous studies demonstrating the abundance of these insects primarily forest environments and gradual adaptation to anthropized or suffered some human interference. The presence of Ps. davisi, Th. auraensis, Ny. antunesi and Th. ubiquitalis in the three ecotopes indicate the adaptation of these insects to different habitats. These species are considered vectors or potential vectors, depending on the region of the country in which they are found and can therefore act in Leishmania transmission in the region.

6
  • ENMANUELLA HELGA RATIER TERCEIRO DE MEDEIROS
  •  

    IMPACT OF VIRAL ENDOSSIMBIONT “Leishmania RNA virus" TYPE 1 ON THE SUSCEPTIBILITY OF Leishmania (Viannia) braziliensis STRAINS TO THE ANTIMONIAL

  • Leader : GABRIEL EDUARDO MELIM FERREIRA
  • MEMBRES DE LA BANQUE :
  • ANA FIDELINA GOMEZ GARAY
  • GABRIEL EDUARDO MELIM FERREIRA
  • MARIANA CORTES BOITÉ
  • Data: 23 juin 2020


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  • Leishmaniasis presents itself as an endemic of non-contagious infectious characteristics and of anthropozoonotic character. There are about 350 million people exposed to the risk of contracting this infection and 2 million new cases of this endemic disease are registered annually, with a an estimated 20,000 to 30,000,000 deaths per year worldwide. Treatment of patients with cutaneous leishmaniasis in most countries is performed with the antimonial drug pentavalent (Sb + 5), which may be meglumine antimoniate (Glucantime) or stibogluconate sodium (Pentostam). However, it has been observed in recent years that some strains of Leishmania spp. have less sensitivity to Sb + 5 compounds. One of the possible factors associated with lower sensitivity in the Americas is the presence of the endosymbiont “Leishmania Virus RNA ”type 1 (LRV1) in some strains of Leishmania spp. Faced with the problematic presented, the present work seeks to analyze the groups LRV1 positive and LRV1 negative with in vitro susceptibility to the trivalent antimonial - emetic tartar (Sb + 3), seen in some studies that Sb + 5 is a prodrug and through biotransformation it becomes Sb + 3, form active and toxic antimony. For this, 20 strains of Leishmania braziliensis were selected isolated from patients treated at the Center for Tropical Medicine of Rondônia (CEMETRON) diagnosed with LT, 10 of which harbor the LRV1 symbiote. So far, In vitro tests were carried out with Sb + 3 of 15 strains of L. braziliensis, with 8 LRV1 positive and 7 LRV1 negative. RNA was also extracted from these strains for later quantification of viral load of positive strains for LRV1 and analysis of gene expression related to redox metabolism. The results obtained in the in vitro experiments showed two groups: (i) susceptible and (ii) less susceptible. Of the 15 strains analyzed, 12 presented profiles susceptible and 3 less susceptible. In addition, qPCR was standardized for quantify viral load, as well as analyze Leishmania genes involved in metabolism redox. The results obtained in in vitro susceptibility to the compound Sb + 3 will be correlated with the presence of the endosymbiont LRV1, viral load and gene expression involved in Leishmania redox metabolism. Given the above, it is known that it is extremely understanding the in vitro susceptibility of strains isolated from LT patients because these findings can provide answers of great relevance for the monitoring and treatment of LT and parasitic infection harboring endosymbiont LRV1.

7
  • ANDERSON MACIEL DE LIMA
  • Antiparasitic activity of acid proteins isolated from Bothrops jararacussu snake venom: Phospholipase A2 (BthA-I-PLA2) and Type C Lectin (BjcuL) with antimalarial potential

  • Leader : ANDREIMAR MARTINS SOARES
  • MEMBRES DE LA BANQUE :
  • ANDREIMAR MARTINS SOARES
  • MAISA DA SILVA ARAÚJO
  • MARCOS ROBERTO DE MATTOS FONTES
  • Data: 28 août 2020
    Ata de defesa assinada:


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  • Malaria is an infection caused by protozoa of the genus Plasmodium, and stands out for its high number of cases in tropical regions. In addition, it is characterized by having a therapy that in some localities have strains that have developed resistance to the drugs used. New strategies have been adopted to identify molecules that are effective for treating this disease. The present work aimed to evaluate the in vitro antiplasmodial activity of BjcuL (lectin type C) and BthA-I-PLA2 (phospholipase A2), both isolated from Bothrops jararacussu snake venom. The purification of lectin was performed using as the first chromatographic step an affinity chromatography on agarose-lactose resin, followed by reverse phase C18 column. Electrophoretic and mass spectrometric analysis showed that lectin has a dimeric structure, bind by disulfide bonds, with molecular weight of 16,117 Da for each monomer, constituting a dimeric protein with 32,642 Da. Lectin as well as its inhibition was verified by lactose, galactosamine and EDTA, indirectly demonstrating its affinity for carbohydrate glucose and the dependence by Ca2 + ions with the use of EDTA chelator that inhibited the maintenance of this biological activity. PLA2 purification was performed in 2 chromatographic steps, the first one being ion exchange in CM-Sepharose resin, followed by reverse phase chromatography in C-18 resin, extracting an acid fraction of interest and rechromatographed under the same conditions of the latter one. SDS-PAGE showed the presence of a 15 kDa apparent molecular weight protein compatible with snake phospholipases A2. Enzyme activity was evaluated using the chromogenic substrate 4N3OBA and demonstrated that BthA-I-PLA2 is an enzymatically active phospholipase A2. Next, the antiparasitic potential of venom and isolated proteins were evaluated in vitro against intraerythrocytic forms of Plasmodium falciparum. The results of antiparasitic inhibition against P. falciparum, venom, lectin and PLA2 presented IC50 of 0.31, 0.11 and 0.028 μg/mL, respectively. The evaluation of cytotoxic activity against the HepG2 cell line presented by Lectin and PLA2 showed that the molecules were selective for the parasite and not for the cells, denoting CC50 ≥ 10 with a selectivity index (IS) of 90,9 for Lectin and 357,14 for PLA2. The results underscore the relevance of the study of snake venom as a promising source of active molecules against tropical parasitic diseases that affect mankind and in particular demonstrate the inhibitory potential of P. falciparum parasite growth by the acid proteins isolated from the B. jararacussu snake venom.

8
  • ROBERTA CRISTINA GOMES DE MEDEIROS DA COSTA

  • EVALUATION OF THE EFFECT OF THE INFECTION BY PLASMODIUM BERGHEI AND TREATMENT WITH COARTEM® ON MUSCULAR NOCICEPTION

  • Leader : QUINTINO MOURA DIAS JÚNIOR
  • MEMBRES DE LA BANQUE :
  • FLAVIA SERRANO BATISTA
  • NIDIANE DANTAS REIS PRADO
  • QUINTINO MOURA DIAS JÚNIOR
  • Data: 30 sept. 2020


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  • BSTRACT A better understanding of the biological processes underlying the progression of disease infection is urgently needed to reduce the morbidity and mortality of malaria. Like many diseases caused by protozoan parasites. Several evidences support the harmful effect of malaria on skeletal and cardiac muscle in animals and humans. Malaria has been shown to cause harmful effects in humans, leading to muscle weakness, muscle fatigue, breathing difficulties, kidney and liver failure, and can lead to cardiac myopathies. Most antimalarial drugs used are active against various stages of the blood parasite. Anti-malarial drugs, widely used, have a short clinical life due to the development of parasite resistance to the drug. In addition to the issue of resistance, another concern is that antimalarials are also associated with the development of adverse reactions, of which the ability to affect skeletal and cardiac muscle stands out. Therefore, the present study intends to experimentally evaluate the effect of treatment with antimalarials on the behavioral responses in a model of muscle pain in male Balb / c mice infected with Plasmodium berghei of the ANKA strain.
Thèses
1
  • CLAUDIA SIQUEIRA DE OLIVEIRA
  • Assessment of biological effects induced by marine extracts and investigation of the antimicrobial potential of synthetic peptides obtained from anemone phospholipase A2 Condylacts gigantea
  • Leader : LEONARDO DE AZEVEDO CALDERON
  • MEMBRES DE LA BANQUE :
  • ALEXANDRE DE ALMEIDA E SILVA
  • CAROLINA BIONI GARCIA TELES
  • CESAR LUIZ DA SILVA GUIMARAES
  • LEONARDO DE AZEVEDO CALDERON
  • RUBIANI DE CASSIA PAGOTTO
  • Data: 19 mars 2020


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  • Microbial resistance is a phenomenon developed by several microorganisms including bacteria, fungi, viruses and parasites. Infections caused by microorganisms resistance are generally at increased risk of worse clinical outcomes, death and increases cost health-care. The situation is reported worldwide, it is considered as an emerging global public health problem. Researchers, doctors and professionals in the field to invest in alternatives for the development of new drugs. In this context, studies involving marine invertebrates, as sources of bioactive molecules against pathogenic microorganisms is a line of research that has gained prominence today due to the success with the results obtained. This work we evaluate the biological effects induced by extracts from anemone Condylactis gigantea (CgTotal and CgPede) and investigate the antimicrobial potential of synthetic peptides obtained from phospholipase A2 called CgPLA2. The extracts were evaluated in vitro for the ability to produce hemolysis and cleave fluorescent phospholipids and in vivo for the ability to induce edema and myotoxicity. Cytotoxicity was observed using human tumor cell lines Jurkat (leukemia T) and B16F10 (melanoma). And the antimicrobial investigation was carried out against strains of E. faecalis (Van-A), E. faecalis (Van-B), S. aureus (MRSA) and K. peneumonie multiresistant. The search for epitopes in the CgPLA2 amino acid sequence was performed by comparing similarity between the phospholipase and bioactive peptide sequences deposited in the database. The CgTotal extract was fractionated by molecular exclusion chromatography, followed by ion exchange chromatography and reverse phase in a C18 column. The phospholipase activity of the fraction of interest and isolated molecule was identified by the hydrolysis of 4N3OBA acid. The results showed that CgTotal did not produce hemolysis, did not show phospholipase activity against the fluorescent substrate, did not show to be edematogenic, myotoxic or cytotoxic. CgParede, did not produce indirect hemolysis, did not show phospholipase activity, did not produce edema and myotoxicity, and was not cytotoxic against the B16F10 cell, but produced direct hemolysis and cytotoxicity on the Jurkat cell. Fractionation was efficient for the isolation of an acid molecule with phospholipase activity. Screening for epitopes with antimicrobial activity from the CgPLA2 sequence resulted in three synthetic peptides that did not show toxicity against the tested bacterial strains. The results obtained with this work, demonstrate that the extract of the anemone C. gigantea can be an interesting object of study to explore the cytotoxic potential on tumor cells. The fragments of the phospholipase expressed in this organism, can serve as inspiration for the rational design of synthetic peptides to be prospected against bacterial strains.

2019
Thèses
1
  • UERICA DE ALMEIDA LOPES
  • IDENTIFICATION OF IL28 GENE POLYMORPHISMS IN PATIENTS
    CHRONIC HEPATITIS B IN AN INDIGENOUS POPULATION OF THE STATE OF RONDÔNIA,
    WESTERN AMAZON, BRAZIL

  • Leader : DEUSILENE SOUZA VIEIRA
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • FRANCISCA DE JESUS HOLANDA
  • SORAYA DOS SANTOS PEREIRA
  • Data: 31 mai 2019


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  • Single nucleotide polymorphisms (SNPs) near the locus of interleukin 28B (IL28B; interferon [IFN] -λ-3) have been associated with the virological response and spontaneous clearance of Hepatitis B Virus (HBV). The impact of IL28B SNPs in HBV infected patients is still poorly studied, especially involving indigenous populations. In view of the above, the study aimed at the genotypic identification of the SNPs rs8099917 and rs12980275 of the IL28B gene. This is the first study on the polymorphism of the IL-28B gene in the indigenous population of the state of Rondônia. The study was carried out with the Indian population Warí of the Pole of Guajará-mirim-RO, in which 40 samples were analyzed, including indigenous men and women, with ages ranging from 18 to 70 years and chronic hepatitis B. Samples were analyzed by quantitative Real-Time PCR for DNA-HBV detection and quantification, the genotypic identification of the SNPs was performed by conventional PCR, followed by RFLP technique and sequencing. It was possible to identify the rs8099917 SNP genotypes in 40 samples, the TT genotype was identified in 90% (36/40) of the indigenous, TG genotype in 8% (3/40) and only one indigenous GG homozygote. For SNP rs 12980275 the AA genotype was identified in 67% (27/40) of the indigenous, 13% AG (5/40) and 20% (8/40) for GG. Therefore, the study demonstrated that the indigenous are inactive chronic carriers of HBV, none presents a serological marker of viral replication. For both SNPs the favorable genotype was the most frequent, the genotype TT (rs8099917) and AA (rs12980275), corroborating with the clinic of the indigenous, since there is no evolution of the disease indicating a good prognosis. Taken together, we report that SNPs of IL28B gene may be a candidate for risk factor for progression of hepatitis B and possible influence on HBV clearance. However, the present study genotyped two polymorphisms of the IL28B gene, investigations with other SNPs involved in the immune response are necessary to better understand the influence of the IL28B gene on HBV infection.

2
  • MARIA JOSE DE SOUZA SARAIVA

  • EVALUATION OF THE INFLUENCE OF PARASITEMIA ON MARKERS OF PLACETARY ACTIVATION ANALYZED BY FLOW CYTOMETRY IN PLASMODIUM VIVAX INFECTED PATIENTS

  • Leader : CARLA FREIRE CELEDÔNIO FERNANDES
  • MEMBRES DE LA BANQUE :
  • DEUSILENE SOUZA VIEIRA
  • DHELIO BATISTA PEREIRA
  • LUAN FELIPO BOTELHO SOUZA
  • Data: 17 sept. 2019


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  • Malaria is still one of the major causes of morbidity and mortality in many tropical and subtropical countries. Understanding the pathogenesis associated with Plasmodium vivax malaria has been a challenge in recent years, which makes it study the pathogenic mechanisms of this species. Given the character displayed by vivax malaria, it becomes relevant to study the influence of platelet activation in disease severity. In this sense, the present work investigated the levels of important platelet surface proteins in patients with acute Plasmodium vivax malaria with varying degrees of parasitemia. O The aim of this study was to standardize the techniques to evaluate the expression of platelet activation markers and apply them in the study of malaria, as well as standardize the antibody titration technique, where it was possible to obtain the concentration antibodies that were used. Eleven individuals were evaluated, of which 10 were Plasmodium vivax infected individuals and one were non-Plasmodium infected. In this stage the biomarkers αIIbβ3 portion αIIb - CD41a), P-Selectin (CD62P). It was also analyzed the percentage of the isolation of platelets of all individuals. In both groups (infected individuals and not CD41a expression was observed, representing an average of 98.5% What is expected once, is that this is the first glycoprotein present on the surface. Regarding the expression of P-Selectin (CD62P), in sick individuals there was a low expression of P-Selectin, ranging from 0.28 to 1.07. How much platelet isolation was observed within the platelet gate, an average 97% purity of this isolation. A total of 50,000 events have been acquired. per tube using the Celesta® flow cytometer (Becton Dickinson). For the acquisition and data analysis, the Flowjo software was used, as recommended by the manufacturer and finally the appropriate statistical analysis will be applied to future experiments.
3
  • LIZIANE ROLIM DANTAS
  • EVALUATION OF PHENOTYPIC AND GENETIC DIVERSITY OF ISOLATES OF THE COMPLEX Mycobacterium abscessus FROM PULMONARY INFECTIONS IN THE STATE OF RONDONIA

  • Leader : GABRIEL EDUARDO MELIM FERREIRA
  • MEMBRES DE LA BANQUE :
  • GABRIEL EDUARDO MELIM FERREIRA
  • NAJLA BENEVIDES MATOS
  • MARIA MANUELA DA FONSECA MOURA
  • ARTEMIR COELHO DE BRITO
  • FLAVIA SERRANO BATISTA
  • Data: 4 nov. 2019


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  • Non-tuberculosis mycobacteria (NTM) have been associated with
    with a variety of diseases, including lung, lymph node infections,
    and nosocomial infections, including outbreaks. The Mycobacterium Complex
    abscessus is composed of three subspecies: M. abscessus subsp. abscessus,
    M. abscessus subsp. bolletii and M. abscessus subsp. massiliense, which are
    pathogenic, fast-growing mycobacteria (MCR)
    distribution in the environment. Precise diagnosis of the subspecies of the
    M. abscessus complex is of great importance due to
    clinics and specific therapeutic conduct for each infectious agent. At the
    from 2008 to 2017 were identified by LACEN / RO 170 samples
    positive for NTM in the state of Rondônia, of these 62 (35.8%) were
    belonging to the M. abscessus complex.
    most frequently identified. In order to evaluate characteristics
    phenotypic and genotypic isolates from isolates previously identified as
    belonging to the M. abscessus complex and to separate them at subspecies level,
    phenotypic tests were performed such as: growth time, morphology of the
    colonies, pigment presence, chord factor formation, molecular tests
    using the RFLP / PRA / hsp65 methodology, sequencing regions of the
    16S rRNA, rpoB and hsp65 genes and PCR from erm (41) gene from 16 isolates
    from sputum samples from patients with infection
    between 2008 and 2017 in the state of Rondônia. Of 16
    bacterial isolates analyzed in PRA hsp65, it was possible to confirm that 15
    belonged to the M. abscessus complex, but one isolate showed a pattern of
    distinct band from the other mycobacterial isolates. The analysis of
    sequencing of the 16S rRNA gene, separated the isolates only at
    Partial sequencing of the rpoB and hsp65 genes identified
    M. abscessus Complex at the species level, where 18.7% were
    identified in M. abscessus subsp. abscessus, 37.5% were identified
    as M. abscessus subsp. bolletti, 37.5% were identified as M.
    abscessus subsp massiliense and 6.25% identified as M. avium subsp.
    hominissuis. PCR amplification of the erm gene (41) helped in the identification
    subspecies and confirmed the identification of five M. abscessus isolates
    subsp. massiliense, but there was a case of M. abscessus subsp. massiliense
    identified by sequencing and not by the erm gene (41). The results of the
    analyzes have shown that the phenotypic evidence currently used is not
    differentiate mycobacteria from the M. abscessus complex and that the
    partial sequencing of the rpoB and hsp65 genes were able to distinguish the
    three subspecies, but as there are reports of horizontal gene transfer,
    Using these two markers, the need to identify
    new targets or combination of targets to overcome the transfer problem
    of genes between M. abscessus complex mycobacteria.

Thèses
1
  • JORGE JAVIER ALFONSO RUIZ DIAZ
  • CRUZAIN FROM Trypanosoma cruzi: PROSPECTION AND IDENTIFICATION OF INHIBITORS WITH POTENTIAL TRYPANOCIDAL ACTIVITY

  • Leader : LEONARDO DE AZEVEDO CALDERON
  • MEMBRES DE LA BANQUE :
  • LEONARDO DE AZEVEDO CALDERON
  • SORAYA DOS SANTOS PEREIRA
  • GABRIEL EDUARDO MELIM FERREIRA
  • MARCOS ROBERTO DE MATTOS FONTES
  • LEILA DE MENDONÇA LIMA
  • Data: 27 juin 2019


  • Afficher le Résumé
  • Chagas Disease (CD), caused by protozoan Trypanosoma cruzi, is considered to be a neglected tropical disease by the World Health Organization. It affects approximately seven million people around the world, with Latin America having the highest number of affected people. Clinically CD presents itself as a biphasic disease, in which the chronic-phase is defined by reduced pharmaceutical therapy efficiency. Other limitations are related to the severe secondary effects and the notification of resistance cases. Under these circumstances it is crucial to develop new strategies addressing the identification of molecules inclined to be alternatives or complements to current chemotherapy. Therefore, involving cruzain, from T. cruzi, the primary cysteine protease in key process from this parasite life cycle, as proliferation, differentiation, cell invasion and host immune system evasion, causes this protease to be an interesting molecular target for exploration. Considering the aforementioned, the objective of this study was to identify inhibitors of recombinant cruzain with potential trypanocidal activity. Thus, recombinant cruzain was obtained by heterologous expression using prokaryote system in zymogen form and sequentially activated by autoproteolysis, resulting in a protein with approximately 23 kDa of molecular mass. Afterwards, searching for potential cruzain inhibitors, previous studies reported a cystatin from Austrelaps superbus venom (AsCystatin) capable of inhibiting catalytic activity from cysteine protease. Evaluating in silico interactions between the potential inhibitor and cruzain, a tridimensional model was obtained by homology modelling, followed by interaction analysis by molecular docking, in which it was possible to observe that key regions for cruzain’s catalytic activity interacts with AsCystatin. Considering these results, it was decided to express recombinant AsCystatin in E. coli, obtaining the protein in a high-level of purity and approximately 14 kDa of molecular weight. Following tests included the evaluation of AsCystatin inhibition of cruzain, resulting in an IAE50 of 21.2 µM. Based on previous in silico analysis, natural and modified peptides were designed, enabling the identification of four peptides capable of inhibiting cruzain’s enzymatic activity. Finally, three peptides showed trypanocidal activity showed in vitro against epimastigote forms of T. cruzi. In conclusion, in this work it was possible to identify AsCystatin and four peptides derived from this protein with inhibitory activity on cruzain, highlighting the in vitro cytotoxic activity associated with these peptides against T. cruzi epimastigote forms.

2
  • ANA PAULA AZEVEDO DOS SANTOS
  • Evaluation of the in vitro and in vivo antileishmanial activities of synthetic compounds derived from Methoxybenzene  

  • Leader : LEONARDO DE AZEVEDO CALDERON
  • MEMBRES DE LA BANQUE :
  • LEONARDO DE AZEVEDO CALDERON
  • CESARINO JUNIOR LIMA APRÍGIO
  • NIDIANE DANTAS REIS PRADO
  • VIVIANE KROMINSKI GRAÇA DE SOUZA
  • GEISA PAULINO CAPRINI EVARISTO
  • Data: 28 juin 2019
    Ata de defesa assinada:


  • Afficher le Résumé
  • Leishmaniasis is a set of diseases caused by protozoa of the genus Leishmania. It presents clínical manifestations in humans that can compromise the skin, mucosa and guts. The available therapeutic options for the treatment of leishmaniasis are based on the use of pentavalent antimonials Pentamidine and Amphotericin B, which have low efficacy, side effects and, more recently, the occurrence of resistance by the parasite to these drugs. The factors presented prompt the search for new compounds with antileishmanial activity and lower toxicity. In this context, the present study aimed to evaluat the in vitro and in vivo leishmanicidal activity of synthetic analogs derived from methoxybenzene obtained commercially from Sigma-Aldrich. The in vitro screening was performed against L. (L.) amazonensis and L. (L.) infantum promastigotes, in which the parasites were treated with serial concentrations of the compounds at 1260- 19.68 μM for 72 hours. Analogs that had a 50% inhibitory concentration of the parasites (IC50) were subsequently selected to evaluate their cytotoxic potential against THP-1, HepG2, VERO and murine macrophages - MØ cells and their hemolytic activity. Cytotoxicity assays were performed using the MTT method. After cytotoxic evaluation on THP-1 cells, the compounds were evaluated at non-cytotoxic concentrations (80- 0.078 μM) to these cells for their in vitro action against L. (L.) amazonensis amastigotes. The assays against promastigotes (IC50) and amastigotes (ICA50) were performed by the Alamarblue method. The in vitro results showed that of the 25 analogs tested, three of them (CCA, S4 and X23) were active against promastigotes of L. (L.) amazonensis and L. (L.) infantum, with IC50 values ranging from 13.84 to 74 μM. Regarding the cytotoxicity, they presented cytotoxic concentration to 50% of the cells (CC50) between 30-302 μM towards THP-1, between 44-1,260 μM for HepG2, between 28-1,260 μM for Vero and between 13-149 μM for MØ. Tests performed against amastigotes revealed that S4 and X23 were even more active against this form, presenting ICA50’s between 10 and 9 μM, respectively, both with selectivity indexes (CC50/ICA50) above 10. The analog CCA did not present activity against amastigotes. No hemolytic activity was observed at the highest concentration for any compound. In the in vivo experiments, mice infected with L. (L.) amazonensis were treated for 10 days, on alternate days, with a total of five days of application with the analog S4 and amphotericin B. Stability of the lesion volume was observed, in addition to reducing the parasite burden for Amphotericin B. For the compound S4, tested at 50 mg/kg, a 90% decrease in the parasite burden was observed, but not flowed by a decrease in footpad swelling. Subsequent to the in vivo antileishmanial evaluation, toxicological tests were performed to evaluate hepatic enzyme production (TGO and TGP) and the concentration of urea and creatinine, which could indicate a possible hepatic and renal toxicity after treatment with S4. After the observation of the potential in vivo antileishmanial activity experiments, action mechanism assays were performed. As a result, the occurrence of morphological and biochemical alterations in L. (L.) amazonensis promastigotes, treated with IC50 and IC90 values of the S4 analogue, was observed, causing the decrease of cellular volume, increase of reactive oxygen species, depolarization of the mitochondrial membrane and autophagic processes, consequently leading to parasite death. In conclusion, this study led to the identification of three analogues (X23, CCA and S4) with antileishmanial activity in vitro and one analog (S4) with in vivo activity against L. (L.) amazonensis and its possible mechanism of action. The results obtained in this study showed unpublished data related to the antileishmanial activity of S4 and allow the continuation of the studies for the search of drugs that act against leishmaniasis.

3
  • GRACIANNY GOMES MARTINS


  • Identification of a peptide derived from an in vitro inhibitory action of Bothrops moojeni metalloprotease on a Plasmodium falciparum pure nucleoside phosphorylase (PfPNP) enzyme.

  • Leader : ANDREIMAR MARTINS SOARES
  • MEMBRES DE LA BANQUE :
  • ANDREIMAR MARTINS SOARES
  • CAROLINA BIONI GARCIA TELES
  • VIVIANE KROMINSKI GRAÇA DE SOUZA
  • GEISA PAULINO CAPRINI EVARISTO
  • MARCOS ROBERTO DE MATTOS FONTES
  • RUDSON DE JESUS HOLANDA
  • SORAYA DOS SANTOS PEREIRA
  • Data: 12 nov. 2019


  • Afficher le Résumé
  • There is a growing need for research on new antimalarial agents for Plasmodium falciparum infection, based mainly on rational drug planning for specific molecular targets in the parasite, as the emergence of resistance to most drugs for malaria treatment has been widely reported. reported. Therefore, the general objective of this study was to evaluate the activity of a metalloprotease of Bothrops moojeni (BmooMPα-I) against Plasmodium falciparum in vitro and by in silico studies, to map and identify for the first time peptide regions with potential inhibitory action. of P. falciparum purine nucleoside phosphorylase enzyme (PfPNP), an enzyme necessary for parasite survival. BmooMPα-I was initially isolated by reverse phase and cation exchange chromatography, and then in vitro assays for antiparasitic activity against P. falciparum W2 strain were performed. For in silico assays, the interactions between BmooMPα-I and PfPNP were evaluated via molecular docking and the resulting peptide, called Pep 1 BM, was selected according to the region of BmooMPα-I with the best interaction target with the target. interest. The values for specific PfPNP reaction activities were measured using the inorganic phosphate substrate and MESG. The fraction corresponding to BmooMPα-I was identified as fraction 4 in the cation exchange chromatography step, due to proteolytic activity on casein and the presence of a 23 kDa main band. BmooMPα-I was able to inhibit in vitro growth of P. falciparum W2, with an IC50 value of 16.14 µg / mL. Pep1 BM virtual screening demonstrated two binding regions with the PfPNP target, with ∆G values at the interaction interface of -10.75 kcal / mol and -11.74 kcal / mol. Multiple alignment analysis of class PI snake metalloprotease sequences with Pep 1 BM peptide demonstrated that this region is not conserved in other species. A significant reduction in PfPNP enzymatic activity was noted due to the presence of Pep 1 BM when compared to the in vitro activity assay of this enzyme in the absence of this possible inhibitor. When evaluating the in vitro antiparasitic activity of the peptide, an IC50 value of ≥ 200 µg / mL was observed, not showing significant in vitro activity against P. falciparum W2. The in silico techniques identified Pep 1 BM peptide with potential affinity binding to the PfPNP catalytic site and its ability to inhibit its enzymatic activity in vitro. Further studies of molecular modification are necessary to propose strategies that favor the physicochemical characteristics of the peptide, such as its hydro and liposolubility profile, molecular mass and ionization coefficient, in order to obtain a derivative capable of reproducing the inhibitory biological effect on the PfPNP target in in vitro experiments against P. falciparum This study provided perspectives for continuity of Pep 1 BM molecule assays and could be directed to the development of biologically active analogs that can have their activities improved through deletion, addition and rational modification of the amino acid sequence, allowing to expand molecular diversity and improve properties. to propose potential new therapies for the treatment of malaria.

2018
Thèses
1
  • ANA FIDELINA GOMEZ GARAY
  • Trypanothione reductase of Leishmania braziliensis as a molecular target for prospecting for new inhibitors: Evaluation of LAAO of Crotalus atrox with antiparasitic activity.

  • Leader : ANDREIMAR MARTINS SOARES
  • MEMBRES DE LA BANQUE :
  • ANDREIMAR MARTINS SOARES
  • FERNANDO BERTON ZANCHI
  • LUIS ANDRE MORAIS MARIÚBA
  • MICHELLE DE OLIVEIRA E SILVA
  • SORAYA DOS SANTOS PEREIRA
  • Data: 23 nov. 2018


  • Afficher le Résumé
  • According to data from the World Health Organization (WHO), about 1 million new cases of Leishmaniasis arise annually. Chemotherapy is based on the drugs ability to interfere in the survival of the parasite presenting several limitations, potentiating this neglected disease as a serious health problem. Approaches in the search for alternatives to treatment using molecular targets of Leishmania spp. are being developed by several research groups. Among these molecular targets are the enzymes involved in essential parasite pathways, such as trypanothione reductase (TR), involved in oxidative stress combating generated by the reactive oxygen species produced by host macrophages during infection. This work aimed to investigate the TR reductase from Leishmania braziliensis as a molecular target for the prospection of new inhibitors and subsequent evaluation of the LAAO of Crotalus atrox with antiparasitic activity. The recombinant protein was expressed in its active homodimeric form, each monomer with estimated molecular mass of 54 kDa and isoelectric point of 6.0. Primary structure analysis of the expressed enzyme revealed a high percentage of identity with the TR's of several trypanosomatids. In order to identify potential inhibitors, the animal poisons biodiversity was prospected assessing inhibitory capacity of the L-amino acid oxidase (LAAO) venom fraction of Crotalus atrox against the recombinant molecular target (IC50: 119 μg/ml). Later, in vitro leishmanicidal activity against L. amazonensis (IC50: 1.8 μg / mL) and L. braziliensis (IC50: 1.3 μg / mL) promastigotes was evaluated and sequentially, the CC50 was determined on cells THP1 (291.38 μg/mL); J774.A1 (24.16 μg/ml); HepG2 (4.05 μg/mL) and VERO (1.95 μg/mL). Molecular modeling by homology was performed for LAAO and TRLb, molecular docking between the two proteins and virtual screening between peptides derived from the primary structure of LAAO against the parasite enzyme. In silico studies allowed the identification and synthesis of 5 peptides which interacted in key regions of the enzyme. In addition, 2 peptides with microbicidal activity were tested to evaluate the inhibitory potential of TR. In this study, the leishmanicidal potential of the LAAO fraction of the C. atrox venom and the identification of the peptide 353RFIYY357, which has in vitro inhibitory activity against TR (IC50: 287,5 μM), was demonstrated. The promising results obtained in this work suggest further research aimed at evaluating the leishmanicidal potential of the peptide and proposing structures derived from this inhibitor capable of adding the antiparasitic effect.

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