Format

Send to:

Choose Destination
See comment in PubMed Commons below
PLoS One. 2011;6(12):e28781. doi: 10.1371/journal.pone.0028781. Epub 2011 Dec 12.

Distribution and regulation of the mobile genetic element-encoded phenol-soluble modulin PSM-mec in methicillin-resistant Staphylococcus aureus.

Author information

  • 1Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, United States of America.

Abstract

The phenol-soluble modulin PSM-mec is the only known staphylococcal toxin that is encoded on a mobile antibiotic resistance determinant, namely the staphylococcal cassette chromosome (SCC) element mec encoding resistance to methicillin. Here we show that the psm-mec gene is found frequently among methicillin-resistant Staphylococcus aureus (MRSA) strains of SCCmec types II, III, and VIII, and is a conserved part of the class A mec gene complex. Controlled expression of AgrA versus RNAIII in agr mutants of all 3 psm-mec-positive SCCmec types demonstrated that expression of psm-mec, which is highly variable, is controlled by AgrA in an RNAIII-independent manner. Furthermore, psm-mec isogenic deletion mutants showed only minor changes in PSMα peptide production and unchanged (or, as previously described, diminished) virulence compared to the corresponding wild-type strains in a mouse model of skin infection. This indicates that the recently reported regulatory impact of the psm-mec locus on MRSA virulence, which is opposite to that of the PSM-mec peptide and likely mediated by a regulatory RNA, is minor when analyzed in the original strain background. Our study gives new insight in the distribution, regulation, and role in virulence of the PSM-mec peptide and the psm-mec gene locus.

PMID:
22174895
[PubMed - indexed for MEDLINE]
PMCID:
PMC3236207
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Public Library of Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk