RESUMO
Aim: The present study was aimed to determine the antimicrobial resistance and Methicillin resistance gene of MRSA isolated from different clinical sources with a comparative study between phenotypic and genotypic methods in respect of accuracies
Methods: A total 49 isolates of MRSA were studied for antibiotic susceptibility pattern, oxacillin and cefoxitin disc diffusion test, SDS_PAGE analysis, DNA extraction and mecA resistant gene detection by PCR
Results: The study included 49 phenotypically detected MRSA isolates by convential methods. All MRSA isolates were resistant to cefoxitin. Although vancomycin was the first drug of choice in treatment for MRSA, it shows a certain resistant for 8.16% of the investigated isolates which is known as VRSA. The result of oxacillin disc diffusion test indicated that 43 isolates were MRSA, although all the tested isolates were considered MRSA according to the results of cefoxitin disc diffusion test. SDS-PAGE showed high degree of similarity among the banding patterns of MRSA. Detection of mecA gene reveled that, it was amplified on chromosomal DNA of 41 out of 49 isolates. Despite all isolates were proved to be a MRSA, only 83.67% gave positive results with PCR