STUDYING THE FREQUENCY OF METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS THROUGH THE MOLECULAR DETECTION OF MECA

Abstract

Background: Methicillin-resistant Staphylococcus aureus is a major cause of serious nosocomial infections and it is very important to have a reliable test to detect these bacteria. mecA encodes the penicillin binding protein 2a, which is associated with staphylococcal methicillin resistance.
Objective:The study was to determine the frequency of methicillin-resistant Staphylococcus aureus in different specimens from Iraqi patients and to genetically characterize and type the samples of methicillin- resistant Staphylococcus aureus through the detection of mec A gene.
Methods: Sixty clinical isolates of Staphylococcus aureus were submitted to DNA extraction. Genomic DNA was submitted to conventional polymerase chain reaction assays, employing MR1-MR2 primers (primer set). The results were compared to the cefoxitin disks agar diffusion method.
Results :Fifty seven of the sixty isolates showed positive results for mecA amplification while three isolates (5%) showed negative results for mecA gene.
Conclusion:Good correlation between the mecA gene detection by PCR and the cefoxitin disk diffusion methods was obtained.
Key words: mecA gene, Staphylococcus aureus, methicillin resistance Staphylococcus aureus