Community-associated Methicillin-resistantStaphylococcus aureus, Canada

• DOI: 10.3201/eid1106.041146
• Publication Date: 2012-03-13T17:00:03Z
• Authors: Michael R. Mulvey; Laura MacDougall; Brenda Cholin; Greg Horsman; Melanie Fidyk; Shirley Woods
• Keywords: Adult; 0301 basic medicine; Canada; Staphylococcus aureus; Adolescent; Bacterial Toxins; Exotoxins; MRSA; Infectious and parasitic diseases; RC109-216; Microbial Sensitivity Tests; Communicable Diseases, Emerging; 03 medical and health sciences; Bacterial Proteins; Leukocidins; Humans; community-associated; Child; Aged; Keywords: antimicrobial resistance; Research; Soft Tissue Infections; R; Middle Aged; Staphylococcal Infections; Saskatchewan; Anti-Bacterial Agents; 3. Good health; Community-Acquired Infections; Medicine; Methicillin Resistance; Staphylococcal Skin Infections

A total of 184 methicillin-resistant Staphylococcus aureus (MRSA) strains were collected from patients who sought treatment primarily for skin and soft tissue infections from January 1, 1999, to March 31, 2002, in east-central Saskatchewan, Canada. Molecular subtyping analysis using pulsed-field gel electrophoresis showed 2 major clusters. Cluster A (n = 55) was composed of a multidrug-resistant MRSA strain associated with a long-term care facility and was similar to the previously reported nosocomial Canadian epidemic strain labeled CMRSA-2. Cluster B (n = 125) was associated with cases identified at community health centers and was indistinguishable from a community-associated (CA)-MRSA strain identified previously in the United States (USA400). Cluster B remained susceptible to a number of classes of antimicrobial agents and harbored the lukF-PV and lukS-PV toxin genes. Over 50% of both clonal groups displayed high-level resistance to mupirocin. This is the first report of the USA400 strain harboring the lukF-PV and lukS-PV toxin genes in Canada.