Severe Staphylococcus aureus Infections Caused by Clonally Related Community-Acquired Methicillin-Susceptible and Methicillin-Resistant Isolates

Kanokporn Mongkolrattanothai, Susan Boyle, Madelyn D. Kahana, Robert S. Daum

Research output: Contribution to journalArticle

177 Scopus citations


We investigated the genetic relatedness of 5 community-acquired (CA) Staphylococcus aureus isolates obtained from 4 consecutive pediatric patients presenting with sepsis syndrome and severe pneumonia during a 3-week period in 2000. Two patients were infected with methicillin-susceptible S. aureus (MSSA), and 2 were infected with methicillin-resistant S. aureus (MRSA). The pulsed-field gel electrophoresis patterns for the 2 CA-MRSA isolates were identical to each other, as were the patterns for the 3 CA-MSSA isolates. A 2-band difference reflecting the presence of a staphylococcal cassette chromosome mec (SCCmec) element distinguished the CA-MRSA isolates from the CA-MSSA isolates. The small, mobile type IV SCCmec element was present in the CA-MRSA isolates. These data suggest that an insertion or, less likely, a deletion of the SCCmec type IV element occurred in a highly virulent S. aureus background. Staphylococcal toxin genes sea, seh, lukS-PV, and lukF-PV were detected in all isolates. Also, in all isolates, was a partial homolog of seo (seo'). The relationship among these patient isolates strengthens the assumption that CA-MRSA infections may be caused by isolates closely related to MSSA isolates.

Original languageEnglish (US)
Pages (from-to)1050-1058
Number of pages9
JournalClinical Infectious Diseases
Issue number8
StatePublished - Oct 15 2003


ASJC Scopus subject areas

  • Microbiology (medical)
  • Infectious Diseases

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