RESUMEN
The purpose of this study was to determine the prevalence of vancomycinresistant Staphylococcus aureus isolated from clinical samples in Shiraz hospitals. From March to December 2012, 100 S aureus isolates [mainly from wound and blood] were collected from three hospitals in Shiraz, south of Iran, After identification of Staphylococcus aureus by biochemical, microbiological and molecular methods, antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion test for 13 different antibiotics Vancomycin-resistant Staphylococcus aureus isolates were determined by vancomycin agar screening test and PCR for vancomycin resistant genes [vanA and vanB]. The lowest and highest resistance was seen for quinupristin-dalfopristin [n=l] and ampicillin [n=95], respectively Vancomycin agar screening test showed that 37 isolates can grow on these media. Further study by PCR also detected vanA and/or vanB genes in all of these strains Also, 19 isolates showed either vanA or vanB but were susceptible according to vancomycin agar screening test. In total, van A and vanB resistant genes were detected in 34% and 37% of clinical isolates, respectively. The results showed that the frequency of vancomycin resistance genes [vanA, vanB] is very high in Staphylococcus aureus strains isolated from patients in south of Iran. Thus, urgent interventions are needed to keep the emergence and transmission of these isolates to a minimum