呈CAMP阴性Streptococcus agalactiae菌株的CAMP因子编码基因cfb的染色体完全或部分被删除
Xixi Lai1, Meihong Chen1, Jianwei Wang1
1Department of Clinical Laboratory, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, China.
Microbiology spectrum
|April 9, 2025
概括
某些带有删除cfb基因的B组链球菌 (GBS) 菌株可以逃避检测,冒着新生儿感染的风险. 多目标分子测定对于准确的GBS查至关重要.
科学领域:
- 临床微生物学和传染病.
- 分子诊断和细菌遗传学
背景情况:
- 针对B组链球菌 (GBS) 的普遍查和产后抗生素预防 (IAP) 已经减少了早期出现的GBS感染.
- 在cfb基因中染色体缺失的GBS菌株可以在CAMP测试和基于cfb的分子诊断中引起假阴性.
研究的目的:
- 调查CAMP阴性GBS菌株的流行率和特征.
- 评估针对性分析的诊断局限性.
- 分析CAMP阴性GBS菌株中的抗生素耐药性模式.
主要方法:
- 孕妇 (35-37周怀孕) 的培养性阴道拭片用于GBS识别.
- 使用CAMP测试,VITEK-2,qPCR,16S rDNA,血型定型,MLST和全基因组测序来表征CAMP阴性菌株.
- 为cfb基因和抗生素敏感性测试进行PCR.
主要成果:
- 隔离了526个GBS菌株,包括19个 (3.6%) 的CAMP阴性菌株,所有都是血清型III和ST862.
- 在大多数CAMP阴性菌株中确定了完整的cfb基因删除,其中一个菌株显示了C终端删除.
- 与CAMP阳性菌株相比,CAMP阴性菌株对西普洛素和勒沃素的耐药性较低.
结论:
- CAMP阴性GBS菌株,通常是由于cfb基因删除,比以前认为的更为普遍.
- 单个目标的分子分析可能导致错过GBS检测,需要多个目标的方法.
- 对CAMP阴性菌株的独特抗生素耐药性概况需要进一步调查.
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