Prevalence of the Panton-Valentine Leukocidin Gene in Clinical Isolates of Staphylococcus aureus Isolated From Hospitals the Ilam Province of Iran

Background: Panton-Valentine leukocidin (luk-pv) is a cytotoxin that causes leukocyte destruction and tissue necrosis. Objectives: The aim of this study was to determine the prevalence of the pv۱, femA, and mecA genes in staphylococcus aureus isolates from clinical specimens in hospitals in Ilam, Iran. Materials and Methods: One hundred and sixty Staphylococcus aureus isolates were collected from hospitals in Ilam, Iran, and phenotypic and genotypic examinations for methicillin-resistant S. aureus (MRSA) isolates were carried out. The antibiotic profiles of these isolates, and the minimal inhibitory concentration (MIC) of MRSA isolates was determined using the agar dilution method with vancomycin, cefoxitin, and oxacillin. All isolates were examined using polymerase chain reaction (PCR) primers for the femA, mecA, and Panton Valentine leukocidin (luk-pv) genes. Results: The results showed ۹۱ isolates (۵۶.۸۸%) were coagulase-positive, and ۶۹ isolates (۴۳.۱۲%) were coagulase-negative Staphylococcus aureus (CNSA). Out of ۹۱ (۵۶.۸۸%) coagulase-positive staphylococci, ۳۲ isolates (۳۵.۱۶%) were resistant to cefoxitin, and ۳۰ isolates (۳۲.۹۶%) were resistant to oxacillin, using disc diffusion method. PCR revealed the presence of the femA gene (۵۱۰ bp band) in all coagulase-positive isolates (۱۰۰%), and the mecA gene (۵۱۳ bp band) was detected in ۳۲ isolates (۳۵.۱۶%); out of ۳۲ MRSA isolates, ۱۳ isolates (۴۰.۶۲%) were positive for presence of the luk-pv gene (۴۳۳ bp band). Conclusions: The cefoxitin disk diffusion method showed the best results when compared to oxacillin disk, similar to results from detecting the mecA gene in PCR as a golden test. Studies on MRSA that carry the luk-pv gene should continue to provide significant insight into the prevalence and epidemiology of these important resistant pathogens. Also, the rate of pvl gene-producing isolates showed to be relatively high, and it should be detected in all staphylococcal infections.