Banca de DEFESA: ANJO GABRIEL CARVALHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANJO GABRIEL CARVALHO
DATE: 23/05/2022
TIME: 14:00
LOCAL: Sala Virtual Remota
TITLE:

PHENOTYPIC AND MOLECULAR IDENTIFICATION AND CHARACTERIZATION OF Streptococcus agalactiae ISOLATED IN PREGNANT WOMEN IN  PORTO VELHO-RONDÔNIA REGION

KEY WORDS:

Maternal-infant, Bacterial resistance, Neonatal sepsis, Serotyping, Epidemiological surveillance.

PAGES: 135
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

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.

BANKING MEMBERS:
Externa à Instituição - ROSANA ROCHA BARROS - UFF
Externa à Instituição - TATIANA DE CASTRO ABREU PINTO - UFRJ
Presidente - 582.482.422-34 - NAJLA BENEVIDES MATOS - UNIR