Houra Pourghafar - Department of Microbiology, Fars Science and Research Branch, Islamic Azad University, Fars, Iran
Houra Pourghafar - Department of Microbiology, Science Agriculture and Modern Technology Shiraz Branch, Fars Science and Research Branch, Islamic Azad University, Shiraz, Iran
Nour Amirmozafari - Department of Microbiology, Faculty of Medicine, Iran University of Medical Science and Health Services, Tehran,
Masoumeh Anvari - Department of Microbiology, Rasht Branch, Islamic Azad University, Rasht, Iran

Department of Microbiology, Rasht Branch, Islamic Azad University, Rasht, Iran Introduction and Objectives: Methicilin-Resistant Staphylococcus aureus (MRSA) is one of the most important causative agents of nosocomial infections. The present study deals with frequency of PVL gene and its relationship with mecA, SCCmecIV, SCCmec V genes in this bacterium. Materials and Methods: Ninty two clinical isolates of S. aureus were obtained within six months of sampling. Antibiotic sensitivity was conducted by use of Disk Difussion method, and resistance-to-methicilin was tested by Disk oxacillin disk. Those isolates which harbored pvl gene were screened for possession of mecA, SCCmecIV and SCCmec genes using specific primers for each gene. Results: Eight of the isolates harbored mecA gene. There were 18 pvl postive isolates. 5 isolates of SCCmec IVa (27.77), IVb and IVd each of which 2 isolates and 3 isolates of SCCmec IVh were positive, respectively. They were negative in terms of possession of SCCmec IVc and SCCmecV chromosomal casts. Results of accurate Fisher test showed that, in significance level of 0.05, there was no relationships between pvl, mecA and SCCmec IVa,b,c genes. Approximately, 20% of the samples had pvl gene and 50% of them had mecA gene. Almost, 60% contained SCCmec chromosomal casts. Also, SCCmec IVa was the most plentiful trait in the samples. Conclusion: Our study showed that resistance to methicillin rapidly develops in hospital environment. This can be very worrisome for systems of hygienic and therapeutic cares.

Staphylococcus aureus, Leukocidin Panton valentine, SCCmec, mecA.