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The social evolution of bacterial pathogenesis

J Smith1

  • 1Department of Biology, Emory University, Atlanta, GA 30322, USA. jssmith@biology.emory.edu

Proceedings. Biological Sciences
|July 19, 2002
PubMed

Insights

Mobile genetic elements facilitate bacterial pathogen evolution. This study proposes horizontal gene transfer as a mechanism to maintain virulence genes by reintroducing them into

Area of Science:

  • Microbiology and Evolutionary Biology
  • Genetics and Genomics
  • Pathogen Evolution

Background:

  • Bacterial pathogen virulence is often conferred by genes located on mobile genetic elements.
  • Horizontal gene transfer (HGT) plays a significant role in the evolution of bacterial pathogens.
  • The evolutionary advantage of virulence genes residing on mobile elements remains poorly understood.

Purpose of the Study:

  • To propose a hypothetical selective mechanism explaining the mobility of virulence-factor genes.
  • To investigate the role of HGT in maintaining cooperation among bacterial pathogens within a host.

Main Methods:

  • Development of mathematical models to simulate pathogen population dynamics within hosts.
  • Analysis of selective pressures favoring HGT of virulence genes.
  • Exploration of 'cheater' strains that benefit from extracellular virulence factors without producing them.

Main Results:

  • Selection within hosts can favor 'cheater' pathogen strains that exploit extracellular virulence factors.
  • Selection for transmission between hosts favors strains that can reintroduce functional virulence genes via HGT.
  • This process forces 'cheater' strains to produce virulence factors, acting as a novel mechanism for cooperation.

Conclusions:

  • Horizontal gene transfer can be a key mechanism for maintaining virulence genes on mobile elements.
  • HGT can drive the evolution of cooperation among bacterial pathogens.
  • The findings have implications for understanding pathogen virulence and developing novel control strategies.

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