Methicillin-resistant Staphylococcus aureus (MRSA) an important microorganism: determination of its prevalence and evaluation of its associated factors in hospitalized dermatologic patients

Background: Methicillin–resistant Staphylococcus aureus (MRSA) has recently emerged as a worldwide major nosocomial pathogen that causes significant morbidity and mortality. MRSA is frequently colonized on the skin. The aim of this study was to determine the MRSA colonization/infection prevalence and to evaluate the potential risk factors for its development in the hospitalized patients in a referral dermatology ward. Method: In this cross sectional study, 203 patients with cutaneous lesions who were admitted to the dermatology ward of a tertiary teaching hospital from 2008 to 2010 were recruited. Samples were collected during the first 48 hours of admission. S. aureus was identified using gram staining, catalase, and coagulase tests. The disk diffusion method was used for testing the sensitivity of different bacteria to antibiotics. Mueller-Hinton agar was the culture medium used for MRSA susceptibility testing. Result: S. aureus was the most common pathogen that grew in 56.2% (114/203) of isolates. MRSA was found in 35.5% (82/203) of isolates. The duration of the cutaneous lesions, age group, positive history of antibiotic use in past 12 months, and underlying diseases were statistically different between the patients with colonization of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) (P<0.05). Using binomial multivariable logistic regression, it was determined that recent antibiotic therapy and presence of underlying diseases were the risk factors for MRSA colonization. Conclusion: This study showed that MRSA colonization is an important problem in dermatology wards. This finding should be noted for proper selection of antibiotics to treat the patients.