在Klebsiella variicola中,在负频率依赖选择下出现新的非聚合变异
Amandine Nucci1, Juliette Janaszkiewicz1, Eduardo P C Rocha1
1Institut Pasteur, Université Paris Cité, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France.
microLife
|October 2, 2023
概括
在Klebsiella variicola中,一种新的粗和干燥的形态型是由nac或mrkH基因的突变产生的. 这种类似雷达的形态型显示了增加的适应性和宿主分散的潜力,影响了临床感染.
科学领域:
- 微生物学 微生物学
- 进化生物学 进化生物学
- 病变的发生和发病.
背景情况:
- 克莱布西拉 (Klebsiella variicola) 是一种新兴的病原体,引起各种感染,特别是在尿路.
- 关于K. variicola的进化,遗传多样性和种群动态的理解有限.
研究的目的:
- 在K. variicola.中表征一种新型rdar-like (粗和干燥) 形态的出现.
- 研究这种形态型的遗传基础和选择性优势.
- 为了探索人口动态和rdar-like形态型的临床影响.
主要方法:
- 对nac和mrkH基因突变的遗传分析.
- 雷达类形态类型的表型特征 (聚合,生长速度,生物膜形成).
- 在rdar和野生型菌株之间进行竞争分析.
- 在公共数据库中对mrkH突变体进行生物信息分析.
主要成果:
- 在nac或mrkH基因中的突变会产生类似rdar的形态型.
- 在MrkH中的功能丧失减少了3型膜表达,导致聚合减少.
- 类似于rdar的形态型表现出增长速度的增加,减少生物膜的形成,以及在竞争中显著的健身优势.
- 大约8%的天然K. variicola分离物中含有截断的mrkH基因,通常是由于IS元素插入.
结论:
- 类似rdar的形态类型是由特定的遗传突变引起的,并被选择用于减少聚合和增加适应性.
- mrkH基因是这种形态型的关键调节者,自然分离物显示其破坏的证据.
- 减少聚合可能会增强宿主分散和殖民,这表明对系统性感染的潜在临床相关性.
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