Phenotypic Characterization and Risk Factors of Nosocomial Staphylococcus aureus from Health Care Centers

Multidrug resistant Staphylococcus aureus (MDRS) is a serious threat to hospitalized patients globally and now represents a challenge for public health, as community-acquired infections appear to be on the increase in both adults and children. S. aureus colonization has been shown to be a risk factor for community-acquired and nosocomial infections. A total of 130 subjects from the community and 100 subjects from health care-related facilities were evaluated for the prevalence of Staphylococcus aureus colonization and to identify risk factors associated with methicillin-resistant S. aureus (MRSA) and vancomycin resistant S. aureus (VRSA) colonization. Among the community subjects, 35.38% had MRSA and 1.53% VRSA colonization. Subjects from health care-related facilities had a lower MRSA colonization rate (17%) than community subjects and the colonization VRSA has not been found. Age was a risk factor for S. aureus colonization, with subjects under age 20 years or between 60 and 80 years showing higher rates of colonization. In conclusion, a high prevalence of MRSA colonization was observed among people with relationship to the hospital setting. The high level of multiple-drug resistance among community MRSA strains in association with the previously reported excessive use of antibiotics highlights the importance of the problem of antibiotic selective pressure. Our results indicate that the spread of both MRSA and VRSA and the transmission of hospital isolates contribute to the high MRSA/ VRSA burden in the community.