Evaluation of vancomycin Resistance and MecA Gene in Staphylococcus aureus Isolates of nosocomial and community acquired infections in Bandar Abbas in 2017-2018

Introduction and Objectives: Staphylococcus aureus is a gram-positive coccus, known as one of the most important human pathogens. Methicillin resistant S. aureus (MRSA) is a public health concern. Hence, the present study was conducted to determine the pattern of antibiotic resistance and identification of the mecA gene in order to better understand the epidemiology of this bacterium in Bandar Abbas. Materials and Methods: This descriptive cross-sectional study was conducted on 100 clinical isolates of nosocomial and community acquired infections in Payambar-Azam hospital, Bandar Abbas in 2017-2018. To identify methicillin-resistant isolates, Cefoxitin disc(30μg) was used and antimicrobial susceptibility patterns were performed according to the CLSI method against Azithromycin, Tetracycline, Tigecycline, Linezolid, Clindamycin, Ciprofloxacin, and Gentamicin. Minimum inhibitory concentration (MIC) of vancomycin was measured using the E.test method and the presence of mecA gene in MRSA was investigated using PCR method. Results: The highest resistance rates was to Cefoxitin, Tetracycline, Gentamicin, Azithromycin, and Clindamycin. The MIC of Vancomycin was between 0.75 and 5 μg/mL. Thirty-eight (38%) isolates carrying MecA gene, where 50 (50%) isolates were obtained from community and 50 (50%) isolates from hospital-acquired infections. Conclusion: MRSA are increasing threat faced to society and hospitalized patients. Acquired community infections occur in healthy people without any apparent risk factors and can act as a source of transmission to the community. In present, planning to set up appropriate treatment protocols for hospitals and preventing the distribution of MRSA infections in the community is one of the most inevitable and essential requirements.

Keywords:

Staphylococcus aureus , Methicillin Resistance , Drug Resistance , mecA Protein.