• Evaluation of resistance to methicillin and the presence of mecA and pvl genes in the Staphylococcus aureus has been isolated from Valiasr Hospital in Tabriz
  • Sara Naebi,1 Mehdi Ghiamirad,2,*
    1. Microbiology group, Faculty of science, Islamic Azad University Ahar branch, Ahar- Iran
    2. Microbiology group, Faculty of science, Islamic Azad University Ahar branch, Ahar- Iran


  • Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of staph infection that is difficult to treat because of resistance to some antibiotics. Pantone valentine leucocidin PVL is one of the important toxins of this bacterium that causes the walls of host white leucocytes lysis and cause necrosis in the tissues.Various studies have suggested that strongly connection between PVL with MRSA. The aim of this study was to determine the frequency of methicillin resistance and to search for mecA and pvl genes in Staphylococcus aureus isolates isolated from Valiasr hospital in Tabriz.
  • Methods: In this descriptive cross-sectional study, 142 specimens were collected from the patients with initial diagnosis of Staphylococcus aureus and were identified using standard laboratory tests. Isolate resistance to common antibiotics was measured by disk diffusion method and resistance to methicillin was measured by cefoxitin disk method. The presence of mecA and pvl genes in the isolates was evaluated using specific primers and PCR.
  • Results: From all samples, 98 isolates were identified as Staphylococcus aureus. The highest antibiotic resistance was observed against penicillin with 96.2% and the lowest resistance to cotrimaxazole with 16% Multiple antibiotic resistance of MDR was present in 62% of isolates. 26 isolates were identified as methicillin resistance by phenotypic method. The MECA gene was identified in 13 isolates, which were identified by phenotypic method 11 as MRSA isolates and 2 as methicillin-sensitive isolates. No pvl gene was found in any of the isolates.
  • Conclusion: The results of this study showed high and multiple resistance of Staphylococcus aureus to the antibiotics studied. 26% of the isolates were MRSAs, which should be considered a serious issue in different parts of the hospital.
  • Keywords: Staphylococcus aaureus, Methicillin Resistance, mecA, pvl