Nasal colonization by methicillin-resistant coagulase-negative staphylococcus in community skilled nursing facility patients.

Background: Methicillin-resistant coagulase-negative staphylococci (MRCNS) are increasing nosocomial pathogens in acute care hospital patients. However, there is little information on the epidemiology of MRCNS in skilled nursing facilities (SNFs). We report a pilot survey of the prevalence of MRCNS colonization in SNF patients.

Methods: Anterior nasal swabs were plated on oxacillin salt screening agar for selection of MRCNS. Suspected MRCNS were confirmed by coagulase and catalase tests and standard disc-diffusion antimicrobial susceptibility tests.

Results: The overall prevalence of MRCNS was 40% for in-house continuing SNF patients, 49% for newly admitted patients, and 60% for SNF nursing personnel. The prevalence was 13% in a "control" group of nonmedical personnel. Forty-six percent of MRCNS were resistant to ciprofloxacin. The frequency of colonization with MRCNS increased over time. After an average 17 months of facility stay, 32% of noncarriers acquired MRCNS. High frequency of colonization was associated with greater disability.

Conclusion: Colonization with MRCNS is common among SNF patients, who can serve as a reservoir for transfer of such strains to acute care hospitals. Careful infection control practice, including judicious use of antibiotics with frequent handwashing, will remain critical policies for limiting spread of such strains.