Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for hospital and community acquired infections. There are many laboratory methods for detection of MRSA. Chromogenic media have been used for the last few years for the quick detection of MRSA. The aim of this study was to compare the performance of conventional methods and chromogenic media for the detection of MRSA in a tertiary care hospital.Methods: A total of 200 consecutive isolates of S. aureus confirmed by conventional methods, collected in a tertiary care hospital, were used for this study. Cefoxitin and oxacillin disc diffusion test used as conventional methods and chromogenic media, i.e., oxacillin resistant screen agar base (ORSAB) was used for the detection of MRSA. All confirmed MRSA were checked by gold standard mecA base polymerase chain reaction (PCR) method. Results:Out of 200 isolates of S. aureus, 50, 52 and 47 strains were MRSA by cefoxitin disc diffusion method, oxacillin disc diffusion method and ORSAB method, respectively. Specificity was 100%, 98.66%, 98.66% by cefoxitin disc diffusion, oxacillin disc diffusion, and ORSAB method, respectively. Conclusion:In conclusion, cefoxitin disc diffusion was the best for the phenotypic detection of MRSA because their sensitivity and specificity were better than oxacillin and ORSAB.

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Introduction:The pathogenicity of Staphylococcus aureus depends on various bacterial surface components and extracellular proteins. S. aureus expresses a variety of virulence factors, including Panton-Valentine leukocidin (pvl). pvl is a cytotoxin produced by S. aureus that causes leukocyte destruction and tissue necrosis. Despite the presumed importance of pvl as a virulence factor, few data are available on its prevalence among S. aureus isolates in our area.

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