Carvalho Anjo Gabriel, Belém Mayra Gyovana Leite, Rodrigues Renata Santos, da Silva Marcos Eduardo Passos, Dorneles Nagilla Wynne Dos Santos, da Silva Lima Núcia Cristiane, Rodrigues Mariana Delfino, Pinto Tatiana Castro Abreu, Taborda Roger Lafontaine Mesquita, Matos Najla Benevides
Postgraduate Program in Experimental Biology (PGBIOEXP), Oswaldo Cruz Foundation of Rondônia (FIOCRUZ), Porto Velho, Rondônia, Brazil.
Laboratory of Microbiology, Oswaldo Cruz Foundation of Rondônia (FIOCRUZ), Av. Guaporé, 215., Porto Velho, Rondônia, 76812-329, Brazil.
BMC Microbiol. 2025 Jun 7;25(1):361. doi: 10.1186/s12866-025-04077-2.
BACKGROUND: Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of neonatal infections, exhibiting remarkable adaptability. This study aimed to characterize the virulence and resistance profiles of GBS isolates obtained from pregnant women in Porto Velho, Rondônia, within the Brazilian Amazon. GBS strains were isolated and identified from rectovaginal cultures using phenotypic and genotypic methods. Capsule typing and the detection of virulence and resistance genes were performed through polymerase chain reaction (PCR). Antimicrobial susceptibility profiles and in vitro biofilm formation were also assessed. RESULTS: A total of 85 GBS strains were characterized. The most prevalent serotypes were Ia (36.5%) and V (15.3%), followed by Ib (14.1%), II (14.1%), III (11.8%), and VI (8.2%). A high prevalence of virulence genes was observed, including scpB (100%), lmb (97.6%), bca (84.7%), hylB (64.7%), cylE (60%), bac (57.6%), and hvgA (11.8%). All strains were susceptible to penicillin, ampicillin, cefazolin, ceftriaxone, and vancomycin. Non-susceptibility was identified for tetracycline (77.6%), erythromycin (18.9%), chloramphenicol (4.7%), clindamycin (3.5%), and levofloxacin (1.2%). Among the 17 strains non-susceptible to erythromycin and/or clindamycin, the detected phenotypes included M (82.4%), cMLS (11.8%), and L (5.9%), with associated resistance genes erm(A) (5.9%), erm(B) (11.8%), and mef(A/E) (64.7%). Additionally, over 90% of the strains demonstrated strong biofilm formation capacity. CONCLUSIONS: This is the first characterization of GBS in this region, revealing notable virulence and high susceptibility to first-line antibiotics. Six serotypes were identified, including Brazil's second report of serotype VI, emphasizing the genetic and epidemiological diversity of the Amazonian region. Moreover, given that the serotype distribution in this population corresponds to the most prevalent types worldwide, the hexavalent GBS conjugate vaccine could represent a promising strategy for this population, as it would theoretically cover 91.8% of the analyzed strains, if proven effective and made available in Brazil.
背景：无乳链球菌（B族链球菌，GBS）是新生儿感染的主要病因，具有显著的适应性。本研究旨在对从巴西亚马逊地区朗多尼亚州韦柳港的孕妇中分离出的GBS菌株的毒力和耐药性特征进行描述。采用表型和基因型方法从直肠阴道培养物中分离并鉴定GBS菌株。通过聚合酶链反应（PCR）进行荚膜分型以及毒力和耐药基因的检测。还评估了抗菌药物敏感性谱和体外生物膜形成情况。 结果：共对85株GBS菌株进行了特征描述。最常见的血清型为Ia（36.5%）和V（15.3%），其次是Ib（14.1%）、II（14.1%）、III（11.8%）和VI（8.2%）。观察到毒力基因的高流行率，包括scpB（100%）、lmb（97.6%）、bca（84.7%）、hylB（64.7%）、cylE（60%）、bac（57.6%）和hvgA（11.8%）。所有菌株对青霉素、氨苄西林、头孢唑林、头孢曲松和万古霉素敏感。对四环素（77.6%）、红霉素（18.9%）、氯霉素（4.7%）、克林霉素（3.5%）和左氧氟沙星（1.2%）存在不敏感情况。在17株对红霉素和/或克林霉素不敏感的菌株中，检测到的表型包括M（82.4%）、cMLS（11.8%）和L（5.9%），相关耐药基因包括erm(A)（5.9%）erm(B)（11.8%）和mef(A/E)（64.7%）。此外，超过90%的菌株表现出较强的生物膜形成能力。 结论：这是该地区首次对GBS进行特征描述，揭示了显著的毒力和对一线抗生素的高敏感性。鉴定出六种血清型，包括巴西关于血清型VI的第二篇报道，强调了亚马逊地区的遗传和流行病学多样性。此外，鉴于该人群中的血清型分布与全球最常见的类型相对应，六价GBS结合疫苗可能是该人群的一种有前景的策略，因为理论上如果在巴西被证明有效并可获得，它将覆盖91.8%的分析菌株。
Ann Clin Microbiol Antimicrob. 2019-3-28
Antibiotics (Basel). 2021-8-12
Rev Gaucha Enferm. 2021
GMS Hyg Infect Control. 2020-9-29
Crit Rev Microbiol. 2020-5
Zotero 插件