Li Xinran, Wan Lilan, Zheng Xiaoyu, Song Jilu, Yang Yan, Chen Tian, Wang Changjun, Li Juan, Chen Yong, Liu Xiong
Department of Health Statistics, School of Public Health, China Medical University, Shenyang 110122, China; Chinese PLA Center for Disease Control and Prevention, Beijing 100071, China.
Chinese PLA Center for Disease Control and Prevention, Beijing 100071, China; Zhengzhou University College of Public Health, Zhengzhou 450002, China.
Genomics. 2025 Sep;117(5):111084. doi: 10.1016/j.ygeno.2025.111084. Epub 2025 Jul 10.
Group B Streptococcus (GBS) causes severe neonatal infections, leading to high mortality rates. This study aimed to investigate the genetic characteristics of GBS isolates in a hospital setting. Nineteen isolates were identified through a review of preservation and cultivation processes since January 2022, followed by antibiotic susceptibility testing. Whole-genome sequencing (WGS) was used to investigate genetic relationships. Among 19 isolates, serotype V was the most prevalent (n = 7), followed by Ib (n = 6) and III (n = 6). Genomic sequence analysis revealed that 19 isolates belonged to four sequence types (STs) related to four clonal complexes (CCs), namely CC12, CC19, CC327, and CC452. The isolates exhibited high resistance rates to erythromycin (89 %, n = 17), levofloxacin (79 %, n = 15), clindamycin (68 %, n = 13), and tetracycline (53 %, n = 10). The mreA gene was found in all GBS isolates (100 %), while the most prevalent resistance gene was ermB (84 %). Furthermore, the fbsB virulence gene associated with adherence was identified in four serotype V/ST890 GBS isolates. Two isolates with different sequence types (ST10, ST19) were found to have undergone parallel mutations in the gene SE858_09425, which encodes a DNA translocase FtsK. Both exhibited an I259L substitution in a conserved ligand-binding domain, strongly suggesting this site is critical for adaptive evolution. IMPORTANCE: Group B Streptococcus (GBS) is a major pathogen causing severe neonatal infections, such as sepsis and meningitis, with high mortality and morbidity rates. The rising antimicrobial resistance of GBS presents significant challenges for clinical management. This study investigates 19 GBS isolates isolated from neonates in Qingyang, Gansu, focusing on their genetic characteristics and resistance profiles through molecular epidemiological analysis and WGS. The findings offer critical insights into the molecular mechanisms of GBS infections, which can inform infection control measures, improve prevention strategies, and optimize antimicrobial therapies to enhance neonatal healthcare outcomes.
B族链球菌（GBS）可导致严重的新生儿感染，死亡率很高。本研究旨在调查医院环境中GBS分离株的基因特征。通过回顾2022年1月以来的保存和培养过程，鉴定出19株分离株，随后进行药敏试验。采用全基因组测序（WGS）来研究遗传关系。在19株分离株中，血清型V最为常见（n = 7），其次是Ib（n = 6）和III（n = 6）。基因组序列分析显示，19株分离株属于与四个克隆复合体（CCs）相关的四种序列类型（STs），即CC12、CC19、CC327和CC452。这些分离株对红霉素（89%，n = 17）、左氧氟沙星（79%，n = 15）、克林霉素（68%，n = 13）和四环素（53%，n = 10）表现出较高的耐药率。在所有GBS分离株中均发现了mreA基因（100%），而最常见的耐药基因是ermB（84%）。此外，在4株血清型V/ST890 GBS分离株中鉴定出与黏附相关的fbsB毒力基因。发现两株不同序列类型（ST10、ST19）的分离株在编码DNA转位酶FtsK的SE858_09425基因中发生了平行突变。两者在保守的配体结合结构域均表现出I259L替换，强烈表明该位点对适应性进化至关重要。重要性：B族链球菌（GBS）是导致严重新生儿感染（如败血症和脑膜炎）的主要病原体，死亡率和发病率很高。GBS日益增加的抗菌药物耐药性给临床管理带来了重大挑战。本研究调查了从甘肃庆阳新生儿中分离出的19株GBS分离株，通过分子流行病学分析和WGS重点关注其基因特征和耐药情况。这些发现为GBS感染的分子机制提供了关键见解，可为感染控制措施提供参考，改进预防策略，并优化抗菌治疗以改善新生儿医疗结局。
