期刊论文详细信息
PLoS Pathogens
The Cost of Virulence: Retarded Growth of Salmonella Typhimurium Cells Expressing Type III Secretion System 1
Matthias Heinemann1  Arndt Benecke2  Markus Arnoldini3  Martin Ackermann3  Alexander Sturm4  Wolf-Dietrich Hardt4  Jasmine Dormann4  Matthias Benz4 
[1] Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands;Institut des Hautes Études Scientifiques & Institut de Recherche Interdisciplinaire CNRS USR3078 - Universités Lille I+II, Bures sur Yvette, France;Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich and Department of Environmental Microbiology, Eawag, Switzerland;Institute of Microbiology, ETH Zürich, Zurich, Switzerland
关键词: Phenotypes;    Virulence factors;    Bacteria;    Regulator genes;    Gene expression;    Salmonella typhimurium;    Oxygen;    Plasmid construction;   
DOI  :  10.1371/journal.ppat.1002143
学科分类:生物科学(综合)
来源: Public Library of Science
PDF
【 摘 要 】

Virulence factors generally enhance a pathogen's fitness and thereby foster transmission. However, most studies of pathogen fitness have been performed by averaging the phenotypes over large populations. Here, we have analyzed the fitness costs of virulence factor expression by Salmonella enterica subspecies I serovar Typhimurium in simple culture experiments. The type III secretion system ttss-1, a cardinal virulence factor for eliciting Salmonella diarrhea, is expressed by just a fraction of the S. Typhimurium population, yielding a mixture of cells that either express ttss-1 (TTSS-1+ phenotype) or not (TTSS-1− phenotype). Here, we studied in vitro the TTSS-1+ phenotype at the single cell level using fluorescent protein reporters. The regulator hilA controlled the fraction of TTSS-1+ individuals and their ttss-1 expression level. Strikingly, cells of the TTSS-1+ phenotype grew slower than cells of the TTSS-1− phenotype. The growth retardation was at least partially attributable to the expression of TTSS-1 effector and/or translocon proteins. In spite of this growth penalty, the TTSS-1+ subpopulation increased from <10% to approx. 60% during the late logarithmic growth phase of an LB batch culture. This was attributable to an increasing initiation rate of ttss-1 expression, in response to environmental cues accumulating during this growth phase, as shown by experimental data and mathematical modeling. Finally, hilA and hilD mutants, which form only fast-growing TTSS-1− cells, outcompeted wild type S. Typhimurium in mixed cultures. Our data demonstrated that virulence factor expression imposes a growth penalty in a non-host environment. This raises important questions about compensating mechanisms during host infection which ensure successful propagation of the genotype.

【 授权许可】

CC BY   

【 预 览 】
附件列表
Files Size Format View
RO201902016972043ZK.pdf 585KB PDF download
  文献评价指标  
  下载次数:3次 浏览次数:6次