Prevalence of Vancomycin Resistance in Methicillin-Resistant Staphylococcus Aureus

Staphylococcus aureus is one of the most common pathogens in nosocomial infections. Vancomycin is the most important therapeutic drug of choice for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains. Therefore, vancomycin-resistant Staphylococcus aureus (VRSA) or vancomycin-intermediate Staphylococcus aureus (VISA) strains are warnings for the medical community. The aim of this study was to evaluate the prevalence of vancomycin resistance in methicillin-resistant Staphylococcus aureus isolated from the nose of patients hospitalized in Imam Reza Hospital, Kermanshah, Iran. In the present study, 85 strains of methicillin-resistant Staphylococcus aureus were isolated from patients in Imam Reza Hospital and evaluated for vancomycin resistance with microdilution test, Epsilometer test (E-test), and polymerase chain reaction (PCR). None of the strains were completely resistant to vancomycin; however, 39 strains (45.9%) were diagnosed as hetero-VRSA (hVISA) strains. VISA and VRSA strains were not observed in this study which is a promising finding in the treatment of clinical infections due to Staphylococcus aureus in our society. However, in our study, the prevalence of hVISA strain was 45.9%, which is perhaps a sign of the appearance of more resistant strains (VISA and VRSA) in our country in the future.