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Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)
12:18

Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus (MRSA)

Published on: February 9, 2011

Clinical importance of purulence in methicillin-resistant Staphylococcus aureus skin and soft tissue infections

Susan E Crawford1, Michael Z David, Daniel Glikman

  • 1Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA.

Journal of the American Board of Family Medicine : JABFM
|November 10, 2009
PubMed
Abstract

Insights

A purulent skin infection strongly predicts methicillin-resistant Staphylococcus aureus (MRSA) susceptible to clindamycin. This finding helps guide antibiotic choices for MRSA infections, particularly in community settings.

Area of Science:

  • Infectious Diseases
  • Clinical Microbiology
  • Antimicrobial Stewardship

Background:

  • Community-associated MRSA (CA-MRSA) strains show higher susceptibility to non-beta-lactam antibiotics like clindamycin compared to healthcare-associated strains.
  • Identifying clinical predictors for MRSA infections can optimize empiric antibiotic therapy selection.

Purpose of the Study:

  • To determine if clinical characteristics can predict MRSA susceptibility to clindamycin.
  • To guide empiric antibiotic therapy for MRSA infections.

Main Methods:

  • Retrospective analysis of MRSA infections at the University of Chicago Medical Center (2004-2005).
  • Assessment of antimicrobial susceptibilities and molecular characteristics (SCCmec IV, pvl genes) of MRSA isolates.
  • Stratification of patients based on lesion characteristics (purulent vs. nonpurulent SSTIs).

Main Results:

  • 88% of MRSA isolates from purulent skin and soft tissue infections (SSTIs) were clindamycin-susceptible.
  • Purulent SSTI had an 88% positive predictive value for clindamycin-susceptible MRSA.
  • Clindamycin susceptibility and pvl gene presence were significantly lower in nonpurulent SSTIs and invasive MRSA disease.

Conclusions:

  • A purulent MRSA SSTI is a strong predictor of clindamycin-susceptible MRSA.
  • The Panton-Valentine leukocidin (pvl) gene was highly prevalent in purulent SSTI isolates, suggesting its association with community-associated strains.

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