Prevalence of staphylococcus aureus with reduced susceptibility against vancomycin in clinical samples isolate from Mashhad hospitalsduring 2014

Staphylococcus aureus is one of the major causes of nosocomial infections. Recently, increase in its various drug-resistant strains, has increased health problems. Incidence of VRSA (vancomycin resistant Staphylococcus aureus) strains has created many concerns about the treatment of these bacterial infections. The aim of this study was to determine the frequency of Staphylococcus aureus with reduced susceptibility against vancomycinin clinical samples of patientsadmitted to the Ghaem and Imam Reza academic hospitals in Mashhad in 2014. In this cross-sectional study within 7 months, 176 S.aureus isolates obtained from clinical samples and were identified using the biochemical methods. To determine the resistance, the disk diffusion method according to CLSI (Clinical and Laboratory Standards Institute) guidelines was used. The minimum inhibitory concentration (MIC) was evaluated by the agar dilution method and approved by E.test. Of 176 S.aureus isolates,68 strains (64/38%) were methicillin resistant.The results of the agar dilution method represented 55cases of VISA (vancomycin intermediate Staphylococcus aureus) and 6 cases VRSA. But, these results confirm the correct with E.Test standard tapes. Emergence of VISA and VRSA isolates has been limited treatment of infections. Therefore, clinicians must be aware of management of patients who are colonized or infected with VISA and VRSA