cChlorhexidine has been increasingly utilized in outpatient settings to control methicillin-resistant Staphylococcus aureus (MRSA) outbreaks and as a component of programs for MRSA decolonization and prevention of skin and soft-tissue infections (SSTIs). The objective of this study was to determine the prevalence of chlorhexidine resistance in clinical and colonizing MRSA isolates obtained in the context of a community-based cluster-randomized controlled trial for SSTI prevention, during which 10,030 soldiers were issued chlorhexidine for body washing. We obtained epidemiological data on study participants and performed molecular analysis of MRSA isolates, including PCR assays for determinants of chlorhexidine resistance and high-level mupirocin resistance and pulsed-field gel electrophoresis (PFGE). During the study period, May 2010 to January 2012, we identified 720 MRSA isolates, of which 615 (85.4%) were available for molecular analysis, i.e., 341 clinical and 274 colonizing isolates. Overall, only 10 (1.6%) of 615 isolates were chlorhexidine resistant, including three from the chlorhexidine group and seven from nonchlorhexidine groups (P > 0.99). Five (1.5%) of the 341 clinical isolates and five (1.8%) of the 274 colonizing isolates harbored chlorhexidine resistance genes, and four (40%) of the 10 possessed genetic determinants for mupirocin resistance. All chlorhexidine-resistant isolates were USA300. The overall prevalence of chlorhexidine resistance in MRSA isolates obtained from our study participants was low. We found no association between extended chlorhexidine use and the prevalence of chlorhexidine-resistant MRSA isolates; however, continued surveillance is warranted, as this agent continues to be utilized for infection control and prevention efforts.
Skin and soft-tissue infections (SSTIs), particularly those attributed to methicillin-resistant Staphylococcus aureus (MRSA), remain a persistent cause of morbidity in community settings. Over the past decade, ambulatory care and emergency department visits for SSTIs have nearly doubled (1, 2). The emergence of MRSA, especially strain USA300 (3), as a community pathogen is recognized as underlying this surge in SSTI rates (1, 4). Individuals in congregate settings, such as children in day care centers, athletes, inmates, and military personnel, are at increased risk for MRSA SSTIs (5-8).Chlorhexidine, a topical antiseptic, has had a longstanding role in infection prevention in health care settings (9) and has been increasingly utilized in outpatient settings (9). It has been an integral component of prevention and control measures during MRSA outbreaks (5, 10, 11). Additionally, chlorhexidine has been demonstrated to be effective against recurrent MRSA SSTIs (12) and in limiting the household spread of SSTIs (13) and is recommended when MRSA decolonization of individuals is a goal (14). In the absence of an effective S. aureus vaccine (15), chlorhexidine has also been employed as an SSTI prevention strategy among military trainees, a group known to be...