INVESTIGATING THE FREQUENCY OF BLAZ GENE AND MECA GENE IN STAPHYLOCOCCUS AUREUS ISOLATED FROM CLINICAL SAMPLES IN GORGAN

Background and Aim:Staphylococcus aureus is a most common of the main cause of nosocomial infections.Treatment of Staphylococcus aureusinfections has become more complicated with emergence of a methicillin-resistant Staphylococcus aureus (MRSA) strain. The purpose of this study was to investigate the frequency of blaZ (β-lactamase resistance gene) and mecA (methicillin resistance gene) in Staph.aureus isolated from clinical samples by using PCR method in Gorgan.Methods:In this study, within 6 months, 1395-1396, 59 Staph.aureus strains that were collected from clinical samples of medical centers in GORGAN.Antibiotic resistant and β-lactamase production were investigated by phenotypic methods .After the revival of the strains in Monitol Salt Agar , plasmid DNA was extracted by using Phenol Chloroform.Then the frequebcy of β-lactamase gene (blaZ) and methicillin resistant gene (mecA) was determined with specific primers by using PCR method.Results:PCR analysis showed that the most frequency gene was blaZ (100%) and followed by mecA (45/8%) and the isolates that had mecA, were positive blaZ together. Oxacillin resistant strains (5%) and Cefoxitin resistant strains (3%) had mecA.The Staph strains (79/4%) had blaZ and β-lactamase.Conclusion:It is recommended to limit the antibiotic uses without prescription or in unnecessary cases in order to decrease rate of microbial resistance to antibiotics.

Keywords:

staphylococcus aureus , blaZ gene , mecA gene , PCR , Gorgan