ANTIBIOTIC SUSCEPTIBILITY PATTERN AND PREVALENCE OF MECA GENE AMONG CLINICAL ISOLATES OF STAPHYLOCOCCUS AUREUS FROM SANANDAJ, IRAN

Background and Aim:Staphylococcus aureus is one of the main causes of infection in the community and the hospital. This bacterium is becoming increasingly resistant to antibiotics. The resistance of S. aureus to methicillin is due to the presence of mecA gene. The aims of this study were to investigate the antibiotic susceptibility and frequency of mecA in S. aureus isolated from patients in Sanandaj, Iran.Methods:A total of 74 isolates of S. aureus were obtained from different clinical samples of patients admitted to Besat and Tohid hospitals in Sanandaj during 2017. Identification of isolates was performed by biochemical methods. The antibiotic susceptibility test for 11 antibiotics was performed using agar disk diffusion method and E-test (for vancomycin) according to the CLSI 2017 (Clinical and Laboratory Standards Institute). After extraction of DNA from isolates the frequency of mecA gene was investigated using polymerase chain reaction.Results:The most effective antibiotic was vancomycin. Of the 74 isolates, the sensitivity to mupirocin was 98.6%, followed by trimethoprim-sulfamethoxazole 95.9%, linzolide 91.9%, cefoxitin 83.8%, gentamicin 82.4%, tetracycline 75.7%, ciprofloxacin 68.9%, clindamycin 59.5%, erythromycin 45.9%, and penicillin 4.1%. All isolates (100%) were susceptible to vancomycin. Of the 74 isolates, 9 (12.16%) carried the mecA gene.Conclusion:The result of our study showed the high susceptibility of isolates to vancomycin and relatively low prevalence of the mecA in our samples. Therefore, we suggest that vancomycin is a suitable drug for treatment, but care should be taken in order to avoid emergence of antibiotic resistance.

Keywords:

Staphylococcus aureus , Methicillin resistance , Drug resistance