Genetic structure of community acquired methicillin-resistant Staphylococcus aureus USA300

BMC Genomics. 2012 Sep 25;13:508. doi: 10.1186/1471-2164-13-508.

Abstract

Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a significant bacterial pathogen that poses considerable clinical and public health challenges. The majority of the CA-MRSA disease burden consists of skin and soft tissue infections (SSTI) not associated with significant morbidity; however, CA-MRSA also causes severe, invasive infections resulting in significant morbidity and mortality. The broad range of disease severity may be influenced by bacterial genetic variation.

Results: We sequenced the complete genomes of 36 CA-MRSA clinical isolates from the predominant North American community acquired clonal type USA300 (18 SSTI and 18 severe infection-associated isolates). While all 36 isolates shared remarkable genetic similarity, we found greater overall time-dependent sequence diversity among SSTI isolates. In addition, pathway analysis of non-synonymous variations revealed increased sequence diversity in the putative virulence genes of SSTI isolates.

Conclusions: Here we report the first whole genome survey of diverse clinical isolates of the USA300 lineage and describe the evolution of the pathogen over time within a defined geographic area. The results demonstrate the close relatedness of clinically independent CA-MRSA isolates, which carry implications for understanding CA-MRSA epidemiology and combating its spread.

Publication types

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

MeSH terms

  • Base Sequence
  • Community-Acquired Infections / epidemiology
  • Community-Acquired Infections / microbiology*
  • Genetic Variation
  • Genome, Bacterial*
  • Genotype
  • Genotyping Techniques
  • Haplotypes / genetics
  • Humans
  • Methicillin-Resistant Staphylococcus aureus / classification
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Molecular Epidemiology
  • Mutation
  • Sequence Analysis, DNA
  • Soft Tissue Infections / epidemiology
  • Soft Tissue Infections / microbiology
  • Staphylococcal Infections / epidemiology
  • Staphylococcal Infections / genetics
  • Staphylococcal Infections / microbiology*
  • Staphylococcal Skin Infections / epidemiology
  • Staphylococcal Skin Infections / microbiology