Evaluation of prevalence of MepA, MdeA, NorA and NorC genes in Staphylococcus aureus strains isolated from Tehran hospitals

Today some Staphylococcus strains are known as methicillin-resistant Staphylococcus aureus or MRSA causes infections which are resistant to conventional therapies and antibiotics. One of the most important reasons for this resistance is the presence of efflux pumps in these strains. The purpose of this project was to investigate the prevalence of NorA, NorC, MdeA and MepA germs in clinical strains of Staphylococcus aureus.

250 clinical samples were isolated from Tehran hospitals and identified by Staphylococcus aureus strains using microbiological methods. Results of microbial isolation showed that 50 samples (20%) out of them belong to Staphylococcus aureus isolates. Continuously, the resistance of Staphylococcus aureus strains to different antibiotics was investigated by using diffusion disk method. DNA extraction of strains was performed and in order to investigate presence of NorA, NorC, MdeA and MpeA genes by using PCR method.

68% of strains were methicillin resistant (MRSA) and 56% of MRSA strains were also resistant to ciprofloxacin. Also, the results of PCR assay demonstrated that the prevalence level of NorA, NorC, MdeA and MpeA genes in the staphylococcus resistance to ciprofloxacin were 60%, 16%, 6% and 10%, respectively.

According to the prevalence of the efflux pump genes in resistant strains to ciprofloxacin and methicillin, better approaches should be utilized to prevent and treat the infections associated with methicillin-resistant strains.