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Regulated expression of pathogen-associated molecular pattern molecules in Staphylococcus epidermidis: quorum-sensing

Cuong Vuong1, Manuela Dürr, Aaron B Carmody

  • 1Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, 903 S 4th Street, Hamilton, MT 59840, USA.

Cellular Microbiology
|July 9, 2004
PubMed

Insights

Staphylococcus epidermidis produces phenol-soluble modulin (PSM) peptides that activate the immune system. Their production is controlled by the agr quorum-sensing system, impacting host defense activation.

Area of Science:

  • Microbiology
  • Immunology
  • Molecular Biology

Background:

  • Phenol-soluble modulin (PSM) peptides are produced by Staphylococcus epidermidis.
  • PSMs activate the human innate immune response.
  • The agr quorum-sensing system regulates bacterial virulence factors.

Purpose of the Study:

  • To quantify individual PSM components produced by S. epidermidis.
  • To investigate the role of the agr system in PSM production.
  • To determine the impact of agr-regulated PSMs on host immune activation.

Main Methods:

  • Development of a liquid chromatography-mass spectrometry (LC-MS) method for PSM quantification.
  • Analysis of PSM production in 76 S. epidermidis strains.
  • Assessment of TNF-alpha production by human myeloid cells.
  • Measurement of neutrophil chemotaxis.

Main Results:

  • Individual PSM peptides were abundant in most tested S. epidermidis strains.
  • PSM production was strictly regulated by the agr quorum-sensing system.
  • An agr mutant strain showed reduced TNF-alpha production and neutrophil chemotaxis.

Conclusions:

  • The agr quorum-sensing system is critical for regulating PSM production in S. epidermidis.
  • Agr-regulated PSMs play a significant role in activating human host defense mechanisms.
  • Quorum-sensing facilitates S. epidermidis survival by modulating pro-inflammatory PSM production during infection.

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