More Challenges in the Prevention and Management of Community-Associated, Methicillin-Resistant Staphylococcus aureus Skin Disease

Staphylococcus aureus is and has long been a common cause of community-associated skin infections, transmitted mainly by close (skin-to-skin) contact. Methicillin-resistant S. aureus (MRSA), previously seen almost exclusively in association with health care, emerged in the 1990s as a cause of community-associated skin infection (1). In the United States, a single pulsed-field gel electrophoresis type, USA300, has caused most community-associated MRSA infections (2). Outbreaks of S. aureus skin infection have occurred in settings conducive to transmission because of crowding, frequent skin-to-skin contact, compromised skin surfaces, sharing of potentially contaminated personal items, and barriers to maintaining hygiene and cleanliness (3–5).

Community-associated MRSA is typically susceptible to multiple classes of antimicrobial agents (1). When antimicrobial therapy is desired as an adjunct to incision and drainage for uncomplicated skin infections, several oral treatment options are generally available. Although data from controlled clinical trials are lacking, treatment options have included clindamycin, trimethoprim–sulfamethoxazole, and tetracyclines (6). Although susceptibility to agents other than β-lactams and macrolides is still the most common profile, resistance to other agents has been documented in USA300 and other community-associated MRSA types (7–10). In an extreme example, resistance to at least 4 classes of non–β-lactam antimicrobials has been described in community-associated MRSA isolates from children in Taiwan and adults in the United States (7, 8, 10).

In this issue, Diep and colleagues (11) present the results of analyses exploring the epidemiology of MRSA USA300 isolates that contain the conjugative plasmid pUSA03. This plasmid contains genes conferring resistance to erythromycin, clindamycin, and mupirocin, and it has the potential to acquire additional resistance elements (7). The authors refer to pUSA03-positive MRSA strains as “multidrug-resistant USA300.” Diep and colleagues build 2 bodies of epidemiologic evidence to suggest that men who …