TrexAB是一种新型的四环素耐药性决定性在Streptococcus dysgalactiae
Marte Glambek1,2, Morten Kjos3, Marita T Mårli3
1Department of Medicine, Haukeland University Hospital, Bergen, Norway.
Frontiers in cellular and infection microbiology
|July 15, 2025
概括
一种新型的两基因操作子,trexAB,被确定为Streptococcus dysgalactiae中低级四环素耐药性的原因. 这一发现对于更新抗生素敏感性测试断点至关重要.
科学领域:
- 微生物学 微生物学
- 基因组学就是基因组学.
- 抗微生物耐药性 抗微生物耐药性
背景情况:
- 杆菌 (Streptococcus dysgalactiae,SD) 是一个重要的病原体,导致各种感染.
- 许多SD分离体显示,在没有已知的耐药基因的情况下,对四环素的敏感性降低.
- 这种四环素耐药性的遗传基础在很大程度上是未知的.
研究的目的:
- 研究Streptococcus dysgalactiae中低级四环素耐药性的遗传基础.
- 为了在SD分离物中识别表现出降低四环素敏感性的新型耐药性决定因素.
主要方法:
- 对407个SD基因组进行了全基因组关联研究.
- 突变和自然转化被用来淘汰候选耐药基因.
- 对各种抗生素进行了对突变动物和野生类型的敏感性测试.
主要成果:
- 一种新的两基因操作子,trexAB,被确定并与四环素耐药性显著相关.
- 在分析中预测了trexAB编码异构体排放输送器.
- 淘汰trexAB降低了四环素最小抑制度 (MIC) 的16至32倍,而tigecycline的MIC则降低了4倍.
结论:
- 一个新的操作子,trexAB,负责SD中低度四环素耐药性的特征.
- 对trexAB阳性分离物的MIC分布与当前的EUCAST断点重叠.
- 这些发现需要对S. dysgalactiae. tetracycline敏感性断点进行重新评估.
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