Typing of Meticillin Resistant Staphylococcus aureus Strains Isolated from an Animal Husbandry in Tehran

Staphylococcus aureus is a member of normal flora of all animals including humans and poultries, and known as a leading cause of nosocomial infections. The aim of this study was to isolate, analysis of the antibiotic resistance pattern and typing of meticillin resistant S. aureus strains isolated from an animal husbandry in Tehran. Totally 97 isolates of MRSA from animal samples were collected from an animal husbandry in Tehran. All isolates were identified at the species level using standard biochemical test. Susceptibility to 11 antibiotics was determined using disc diffusion method according to guidelines of Clinical Laboratory and Standard institute (CLSI). Minimum inhibitory concentration (MIC) of oxacillin and vancomycin in MRSA isolates were also detected using broth microdilution assay according to CLSI recommendation. Primers for identification of 6 classes of prophages were used in a Multiplex-PCR assay. Sccmec types of MRSA isolates were detected using multiplex-PCR. All MRSA isolates showed resistance to penicillin, ciprofloxacin, erythromycin and tobramycin. Eighty percent of MRSA isolates showed high level resistance (MIC≥256 μ g/ml) to oxacillin. Four different prophage types (SGB, SGF, SGFa and SGFb) and 2 prophage patterns were found in MRSA isolates and. All isolates carried SCCmec type III. High prevalence of SCCmec type III and also high level antibiotic resistance among MRSA strains isolated form animals indicating the hospital origin of these isolates. The results of this study provide the important role of animal samples as reservoirs of MRSA strains.