Methicillin-resistant Staphylococcus aureus: a consensus review of the microbiology, pathogenesis, and epidemiology with implications for prevention and management.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen in community hospitals, long-term-care facilities, and tertiary care hospitals. The basic mechanism of resistance is alteration in penicillin-binding proteins of the organism. Methods for isolation by culture and typing of the organism are reviewed. MRSA colonization precedes infection. A major reservoir is the anterior nares. MRSA is usually introduced into an institution by a colonized or infected patient or health care worker. The principal mode of transmission is via the transiently colonized hands of hospital personnel. Indications for antibiotic therapy for eradication of colonization and treatment of infection are reviewed. Infection control guidelines and discharge policy are presented in detail for acute-care hospitals, intensive care and burn units, outpatient settings, and long-term-care facilities. Recommendations for handling an outbreak, surveillance, and culturing of patients are presented based on the known epidemiology.