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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

Community-associated methicillin-resistant Staphylococcus aureus is prevalent in wounds of community-based injection

E Lloyd-Smith1, M W Hull, M W Tyndall

  • 1British Columbia Centre for Excellence in HIV/AIDS, St Paul's Hospital, Vancouver, BC, Canada.

Epidemiology and Infection
|March 6, 2010
PubMed

Insights

Methicillin-resistant Staphylococcus aureus (MRSA) is common in wounds among injection drug users (IDUs). Community-associated MRSA strains in IDU wounds show concerning antibiotic resistance patterns, particularly to clindamycin.

Area of Science:

  • Infectious Diseases
  • Microbiology
  • Public Health

Background:

  • Injection drug users (IDUs) exhibit increased risk for Staphylococcus aureus carriage, including MRSA.
  • Cutaneous infections linked to injection practices are prevalent in IDUs, yet detailed microbiological studies are limited.

Purpose of the Study:

  • To investigate the microbiology of wound infections in IDUs.
  • To determine the antibiotic susceptibility profiles of Staphylococcus aureus isolates from IDU wounds.
  • To assess the prevalence and characteristics of community-associated MRSA in this population.

Main Methods:

  • Analysis of wound isolates from a subsample of 218 IDUs at a supervised injection facility.
  • Microbiological culture and identification of S. aureus, including MRSA and methicillin-susceptible S. aureus (MSSA).
  • Genotyping for Panton-Valentine leukocidin (PVL) to classify MRSA as community-associated (CA-MRSA).
  • Antibiotic susceptibility testing for various agents.

Main Results:

  • S. aureus was identified in 43% of wound cultures (25 isolates), comprising 14 MRSA and 11 MSSA.
  • 16 of 18 MRSA isolates were classified as CA-MRSA due to PVL gene presence.
  • All CA-MRSA isolates were susceptible to tetracycline, vancomycin, and linezolid, but only 13% were susceptible to clindamycin.
  • Methicillin-susceptible S. aureus (MSSA) showed 63% susceptibility to clindamycin.

Conclusions:

  • Community-associated MRSA is a significant pathogen in wound infections among injection drug users.
  • The high frequency of CA-MRSA and its resistance to clindamycin in this population warrants attention.
  • These findings highlight the need for targeted interventions and surveillance for MRSA in IDU communities.

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