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The Enterococcus faecalis fsrB gene, a key component of the fsr quorum-sensing system, is associated with virulence

Eleftherios Mylonakis1, Michael Engelbert, Xiang Qin

  • 1Division of Infectious Diseases, Harvard Medical School, Boston, Massachusetts 02114, USA.

Infection and Immunity
|July 16, 2002
PubMed

Insights

The fsrB gene, crucial for Enterococcus faecalis quorum sensing, significantly reduces the bacteria's virulence in a rabbit endophthalmitis model. Restoring fsrB function fully reinstated pathogenicity, confirming its role in E. faecalis pathogenesis.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Bacterial Pathogenesis

Background:

  • Quorum sensing (QS) is a cell-to-cell communication mechanism bacteria use to regulate group behaviors.
  • The fsr quorum-sensing system in Enterococcus faecalis regulates various virulence factors.
  • Understanding the role of specific QS genes like fsrB is crucial for developing targeted antimicrobial strategies.

Purpose of the Study:

  • To investigate the role of the fsrB gene in the pathogenicity of Enterococcus faecalis.
  • To evaluate the utility of a rabbit endophthalmitis model for studying bacterial quorum sensing in vivo.

Main Methods:

  • Development of a nonpolar deletion mutant of the fsrB gene in Enterococcus faecalis.
  • Infection of rabbits with wild-type, fsrB mutant, and complemented strains to induce endophthalmitis.
  • Assessment of bacterial virulence and pathogenicity in the established rabbit endophthalmitis model.

Main Results:

  • The fsrB deletion mutant exhibited significantly reduced virulence compared to the wild-type strain.
  • Complementation of the fsrB mutation restored the virulence of the bacteria to wild-type levels.
  • The rabbit endophthalmitis model proved effective in demonstrating the in vivo role of fsrB.

Conclusions:

  • The fsrB gene plays a significant role in the pathogenesis of Enterococcus faecalis.
  • The fsr quorum-sensing system is essential for full virulence of E. faecalis.
  • The rabbit endophthalmitis model is a suitable platform for in vivo studies of bacterial quorum sensing and pathogenesis.

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