A novel methicillin-resistance cassette in community-acquired methicillin-resistant Staphylococcus aureus isolates of diverse genetic backgrounds

J Infect Dis. 2002 Nov 1;186(9):1344-7. doi: 10.1086/344326. Epub 2002 Oct 3.


Until recently, it has been unclear whether community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) isolates represent the spread of hospital MRSA isolates into the community. In 2 CA-MRSA isolates, a novel genetic element, designated staphylococcal cassette chromosome mec (SCCmec) type IV, was found; it differs from SCCmec types I-III in its small size and absence of non-beta-lactam genetic-resistance determinants. To study the prevalence of type IV SCCmec, polymerase chain reaction characterization of SCCmec was performed on DNA from 12 CA-MRSA isolates. The 12 CA-MRSA isolates were from diverse genetic backgrounds, as evidenced by their stratification into 5 pulsed-field gel electrophoresis types, 4 coagulase types, and 2 ribotypes. Eleven of the 12 isolates contained the novel SCCmec type IV element. Ten were resistant only to beta-lactam antibiotics. SCCmec type IV is present on the genome of CA-MRSA isolates. Its relatively small size and presence in isolates of diverse genetic backgrounds suggest that it may spread among S. aureus isolates.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Community-Acquired Infections / transmission*
  • Cross Infection / transmission
  • Humans
  • Methicillin Resistance / genetics*
  • Polymerase Chain Reaction
  • Staphylococcal Infections / transmission*
  • Staphylococcus aureus / classification
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / genetics*