Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana, India.
Department of Statistics, Central University of Haryana, Mahendergarh, Haryana, India.
BMC Microbiol. 2023 Jul 5;23(1):176. doi: 10.1186/s12866-023-02877-y.
Group B Streptococcus (GBS) is a causative agent of various infections in newborns, immunocompromised (especially diabetic) non-pregnant adults, and pregnant women. Antibiotic resistance profiling can provide insights into the use of antibiotic prophylaxis against potential GBS infections. Virulence factors are responsible for host-bacteria interactions, pathogenesis, and biofilm development strategies. The aim of this study was to determine the biofilm formation capacity, presence of virulence genes, and antibiotic susceptibility patterns of clinical GBS isolates.
The resistance rate was highest for penicillin (27%; n = 8 strains) among all the tested antibiotics, which indicates the emergence of penicillin resistance among GBS strains. The susceptibility rate was highest for ofloxacin (93%; n = 28), followed by azithromycin (90%; n = 27). Most GBS strains (70%; n = 21) were strong biofilm producers and the rest (30%; n = 9) were moderate biofilm producers. The most common virulence genes were cylE (97%), pavA (97%), cfb (93%), and lmb (90%). There was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility, according to Spearman's rank correlation analysis.
About a third of GBS strains exhibited penicillin resistance and there was a negative association between having a strong biofilm formation phenotype and penicillin susceptibility. Further, both the strong and moderate biofilm producers carried most of the virulence genes tested for, and the strong biofilm formation phenotype was not associated with the presence of any virulence genes.
B 群链球菌（GBS）是导致新生儿、免疫功能低下（尤其是糖尿病）非孕妇和孕妇各种感染的病原体。抗生素耐药性分析可以深入了解预防潜在 GBS 感染的抗生素预防措施。毒力因子负责宿主与细菌的相互作用、发病机制和生物膜形成策略。本研究旨在确定临床 GBS 分离株的生物膜形成能力、毒力基因的存在和抗生素敏感性模式。
所有测试的抗生素中，青霉素的耐药率最高（27%；n=8 株），这表明 GBS 菌株中出现了青霉素耐药性。对氧氟沙星（93%；n=28）和阿奇霉素（90%；n=27）的敏感性最高。大多数 GBS 株（70%；n=21）是强生物膜形成者，其余 30%（n=9）是中度生物膜形成者。最常见的毒力基因是 cylE（97%）、pavA（97%）、cfb（93%）和 lmb（90%）。根据 Spearman 等级相关分析，强生物膜形成表型与青霉素敏感性之间存在负相关。
约三分之一的 GBS 株表现出青霉素耐药性，且强生物膜形成表型与青霉素敏感性之间存在负相关。此外，强和中度生物膜形成者均携带大多数测试的毒力基因，且强生物膜形成表型与任何毒力基因的存在无关。
