ABSTRACT
Methicillin resistant Staphylococcus aureus (MRSA) is a major pathogen implicated in
healthcare and community associated infections. This study was aimed at determining
the antimicrobial resistance pattern and genotypic characteristics of some clinical MRSA
isolates from federal medical centre Umuahia and Abia State teaching hospital Aba both
in Abia State, Nigeria with respect to resistance and virulence genes. A total of 40 MRSA
isolates identified using cefoxitin discs were obtained from different clinical samples.
Antibiotic resistance to 15 different antibiotics was determined by Kirby-Bauer disc
diffusion method, DNA extraction was by boiling method and gene characterization by
Polymerase Chain Reaction (PCR) with appropriate primers. Results obtained showed
that all isolates were sensitive to vancomycin while all were resistant to cefoxitin and
ceftazidine. Resistance of the organisms to oxacillin, ceftriaxone and augmentin was also
high. PCR analysis revealed that 12 (30%) of the total isolates screened possessed mecA
gene, 7 (17.5%) harbored the beta-lactamase blaZ gene, 8 (20%) possessed the ermB
gene while 4 (10%) carried the pvl gene. The highest incidence of mecA gene was
obtained from wound samples while none was obtained from ear swabs. The study
establishes a high level of multiple drug resistance among the MRSA isolates and
presence of virulence genes in the isolates under study. Therefore, we recommend the
infection control department of the various hospitals in the area to screen for MRSA and
carry out risk factor analysis to determine accurate measures for controlling the spread
of MRSA
KEYWORDS:Antibiotic resistance, MRSA, resistance genes, virulence genes, PCR
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