Detection of the antibiotic resistance pattern in Staphylococcus aureus isolated from clinical samples obtained from patients hospitalised in Imam Reza hospital, Kermanshah

Staphylococcus aureus is one of important etiology of contagious infections in community and hospital (nosocomial infections). Nowadays, an intensive increases in the antibiotic resistance is recorded due to increase in the rate of antibiotic usages worldwide. This study was conducted to track the antibiotic resistant genes in the S. aureus strains isolated from clinical specimens obtained from humans and to determine the antibiotic sensitivity pattern or the strains. In this cross-sectional study, 100 coagulase-positive S. aureus collected from urinary tract infections and skin wounds of the patients hospitalised in the Imam Reza hospital, Kermanshah, through 2012. These strains were selected using laboratory standard methods and culture-specific. The antibiotic susceptibility testing was performed using disk diffusion on plate. Furthermore, the presence of 5 genes responsible for antibiotic resistance, including mecA, aacA-D, tet K, tet M, msrA, ermA, were investigated using multiplex-PCR method. Based on the phenotypic investigation on antibiotic resistance of S. aureus strains, the highest rates were seen in treatment with penicillin (90%), tetracycline (76%), methicillin (64%), ampicillin (55%) while the lowest sensitivity was observed in treatment with nitrofurantoin (8%) and vancomycin (14%). The most prevalent gene was tetM (89%), followed by mecA (58%), ermA (40%), msrA (36%), aacA-D (24%) and  tetK (13%). Our result showed high rates of antibiotic resistance in the S. aureus isolated from this hospital. Therefore, it is recommended to limit the antibiotic uses without prescription or in unnecessary cases in order to decrease rate of microbial resistance to antibiotics.