Banca de QUALIFICAÇÃO: NAJARA AKIRA COSTA DOS SANTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : NAJARA AKIRA COSTA DOS SANTOS
DATE: 07/07/2022
TIME: 14:00
LOCAL: Sala Virtual Remota
TITLE:

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KEY WORDS:

Bacterial composition; Antibiotic treatment; Salivary gland; Midgut; Susceptibility; Malaria vector

PAGES: 94
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

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 Fiocruz Rondônia and field mosquitoes were collected by protected human landing collection. We are sequencing the V4 hypervariable region of the 16S rRNA gene to profile the microbiota composition. 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 α-diversity, the Shannon and Simpson indices are being estimated, and for β-diversity the Bray-Curtis and Unifrac measures. 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 high dominance of OTUs in their microbiota communities. The standardized and sterile rearing conditions during the colonization process may have led to the less diversity and dominancy by few species. Although the difference in bacterial composition, the organs shared a core microbiota. Furthermore, the abundance of bacteria such as, Asaia and Pseudomonas during the period of P. vivax infection will be important to understand their relation on P. vivax-An. darlingi interaction because these bacteria have blocking activity in the development of Plasmodium. 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 raises the question whether the An. darlingi-P.vivax-microbiota interaction could be different from what is known for others Plasmodium spp. and anopheline combinations. The microbiota characterization of field-caught An. darlingi and infected mosquitoes are being performed to analyses and conclusion of the study.

BANKING MEMBERS:
Externa à Instituição - ANA CRISTINA BAHIA NASCIMENTO - UFRJ
Externo à Instituição - MARCELO JACOBS-LORENA
Presidente - 582.482.422-34 - NAJLA BENEVIDES MATOS - UNIR