沙门氏菌中毒力基因的双稳态表达导致形成抗生素耐受亚群。

Bistable expression of virulence genes in salmonella leads to the formation of an antibiotic-tolerant subpopulation.

作者信息

Arnoldini Markus, Vizcarra Ima Avalos, Peña-Miller Rafael, Stocker Nicolas, Diard Médéric, Vogel Viola, Beardmore Robert E, Hardt Wolf-Dietrich, Ackermann Martin

机构信息

Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland; Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland.

Laboratory of Applied Mechanobiology, Department of Health Science and Technology, ETH Zurich, Zurich, Switzerland.

出版信息

PLoS Biol. 2014 Aug 19;12(8):e1001928. doi: 10.1371/journal.pbio.1001928. eCollection 2014 Aug.

Abstract

Phenotypic heterogeneity can confer clonal groups of organisms with new functionality. A paradigmatic example is the bistable expression of virulence genes in Salmonella typhimurium, which leads to phenotypically virulent and phenotypically avirulent subpopulations. The two subpopulations have been shown to divide labor during S. typhimurium infections. Here, we show that heterogeneous virulence gene expression in this organism also promotes survival against exposure to antibiotics through a bet-hedging mechanism. Using microfluidic devices in combination with fluorescence time-lapse microscopy and quantitative image analysis, we analyzed the expression of virulence genes at the single cell level and related it to survival when exposed to antibiotics. We found that, across different types of antibiotics and under concentrations that are clinically relevant, the subpopulation of bacterial cells that express virulence genes shows increased survival after exposure to antibiotics. Intriguingly, there is an interplay between the two consequences of phenotypic heterogeneity. The bet-hedging effect that arises through heterogeneity in virulence gene expression can protect clonal populations against avirulent mutants that exploit and subvert the division of labor within these populations. We conclude that bet-hedging and the division of labor can arise through variation in a single trait and interact with each other. This reveals a new degree of functional complexity of phenotypic heterogeneity. In addition, our results suggest a general principle of how pathogens can evade antibiotics: Expression of virulence factors often entails metabolic costs and the resulting growth retardation could generally increase tolerance against antibiotics and thus compromise treatment.

摘要

表型异质性可赋予生物体的克隆群体新的功能。一个典型的例子是鼠伤寒沙门氏菌中毒力基因的双稳态表达,这导致了表型有毒和表型无毒的亚群。已证明这两个亚群在鼠伤寒沙门氏菌感染过程中进行分工。在此,我们表明该生物体中异质性毒力基因表达还通过一种风险对冲机制促进了对抗生素暴露的生存能力。我们使用微流控装置结合荧光延时显微镜和定量图像分析,在单细胞水平分析了毒力基因的表达,并将其与暴露于抗生素时的生存情况相关联。我们发现,在不同类型的抗生素以及临床相关浓度下,表达毒力基因的细菌细胞亚群在暴露于抗生素后显示出更高的存活率。有趣的是,表型异质性的这两种结果之间存在相互作用。通过毒力基因表达异质性产生的风险对冲效应可以保护克隆群体免受利用并破坏这些群体内部分工的无毒突变体的影响。我们得出结论,风险对冲和分工可以通过单一性状的变异产生并相互作用。这揭示了表型异质性在功能复杂性上的一个新程度。此外,我们的结果提出了病原体如何逃避抗生素的一般原则:毒力因子的表达通常需要代谢成本,由此导致的生长迟缓通常会增加对抗生素的耐受性,从而影响治疗效果。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/058a/4138020/04c1d55e13f5/pbio.1001928.g001.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索