Prevalence of Vancomycin Resistance in Methicillin-Resistant Staphylococcus Aureus

Abstract

Background & Aims: 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. Methods: 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). Results: None of the strains were completely resistant to vancomycin; however, 39 strains (45.9%) were diagnosed as hetero-VRSA (hVISA)strains. Conclusion: 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.