Comparative analysis of virulence and toxin expression of global community-associated methicillin-resistant Staphylococcus aureus strains

J Infect Dis. 2010 Dec 15;202(12):1866-76. doi: 10.1086/657419. Epub 2010 Nov 4.

Abstract

The current pandemic of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin infections is caused by several genetically unrelated clones. Here, we analyzed virulence of globally occurring CA-MRSA strains in a rabbit skin infection model. We used rabbits because neutrophils from this animal species have relatively high sensitivity to Panton-Valentine leukocidin (PVL), a toxin epidemiologically correlated with many CA-MRSA infections. Virulence in the rabbit model correlated with in vitro neutrophil lysis and transcript levels of phenol-soluble modulin α and α-toxin, but not PVL genes. Furthermore, abscesses caused by USA300 and its PVL-negative progenitor USA500 were comparatively large and similar in size, suggesting that PVL has played a limited role in the evolution of USA300 virulence in the context of skin infections. Our study indicates a major but not exclusive impact of virulence on the epidemiological success of USA300 and other CA-MRSA strains and emphasizes the importance of core genome-encoded toxins in CA-MRSA skin infections.

Publication types

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

MeSH terms

  • Animals
  • Bacterial Toxins / biosynthesis*
  • Community-Acquired Infections / microbiology*
  • Disease Models, Animal
  • Exotoxins / biosynthesis
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial*
  • Hemolysin Proteins / biosynthesis*
  • Leukocidins / biosynthesis
  • Methicillin-Resistant Staphylococcus aureus / pathogenicity*
  • Neutrophils / microbiology
  • Rabbits
  • Skin / microbiology
  • Skin / pathology
  • Staphylococcal Skin Infections / microbiology*
  • Virulence
  • Virulence Factors / biosynthesis*

Substances

  • Bacterial Toxins
  • Exotoxins
  • Hemolysin Proteins
  • Leukocidins
  • Panton-Valentine leukocidin
  • Virulence Factors
  • staphylococcal alpha-toxin
  • staphylococcal delta toxin