根据实验进化的模型,Legionella pneumophila中耐热冲击的发展
Jeffrey Liang1, Gillian Cameron1, Sébastien P Faucher1,2
1Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue , Québec, Canada.
Applied and environmental microbiology
|September 5, 2023
概括
菌可以在热水系统中发展出耐热性,在巴氏杀菌过程中存活下来. 这种适应涉及热冲击基因的突变,突出显示需要彻底根除以防止持久性细菌.
科学领域:
- 微生物学 微生物学
- 环境健康 环境健康
- 细菌的适应 细菌的适应
背景情况:
- 肺炎菌是医疗机构中严重的医院感染威胁,原因是它存在于复杂的热水配送系统 (HWDS).
- 目前的控制措施,如超热冲洗巴氏杀菌,往往会被缓慢的重新殖民,这表明细菌适应热应激.
研究的目的:
- 调查Legionella pneumophila在现场进化的潜力,以提高在高温条件下的生存率.
- 模仿和理解L. pneumophila的适应机制,以应对与HWDS相关的热应激.
主要方法:
- 采用了适应性实验室进化模型来选择野生型L. pneumophila菌株,以应对短暂的高温暴露.
- 种群遭受了模仿常规热水使用和失败的消毒过程的温度.
主要成果:
- 选择的L. pneumophila种群进化了对55°C的不敏感性,并获得了在短时间暴露在59°C的温度下生存的能力.
- 适应热量的血统表现出更高的热冲击基因表达,这表明预先适应.
- 观察到不同的突变特征,其中DnaJ/DnaK/ClpB分解酶复合体,htpG和clpX的常见突变.
结论:
- 肺炎杆菌可以适应热应激,支持在现场观察抵抗控制措施的情况.
- 关键的伴侣和蛋白酶基因中的突变赋予了热冲击生存,证明了持久性的机制.
- 完全根除L. pneumophila对于防止选择更持久,耐热菌株至关重要,类似于抗生素耐药性的发展.
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