Mutations in agr do not persist in natural populations of methicillin-resistant Staphylococcus aureus

J Infect Dis. 2010 Nov 15;202(10):1593-9. doi: 10.1086/656915. Epub 2010 Oct 13.


Staphylococcus aureus organisms vary in the function of the staphylococcal virulence regulator gene agr. To test for a relationship between agr and transmission in S. aureus, we determined the prevalence and genetic basis of agr dysfunction among nosocomial methicillin-resistant S. aureus (MRSA) in an area of MRSA endemicity. Identical inactivating agr mutations were not detected in epidemiologically unlinked clones within or between hospitals. Additionally, most agr mutants had single mutations, indicating that they were short lived. Collectively, the results suggest that agr dysfunction is adaptive for survival in the infected host but that it may be counteradaptive outside infected host tissues.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Cross Infection / epidemiology
  • Cross Infection / microbiology*
  • Gene Frequency
  • Hospitals, Urban
  • Humans
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Methicillin-Resistant Staphylococcus aureus / pathogenicity
  • Microbial Sensitivity Tests
  • Mutation
  • New York City
  • Quorum Sensing / genetics*
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / microbiology*
  • Trans-Activators / genetics*
  • Virulence / genetics


  • Agr protein, Staphylococcus aureus
  • Bacterial Proteins
  • Trans-Activators