Background: Antibiotic resistance in bacteria has long been recognized as a major health problem occurring worldwide. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) remains a global health problem. MRSA is reported as one of the leading pathogens involved in increased rates of morbidity and mortality amongst patients in Ghana. This study determined the prevalence and resistance mechanisms of MRSA isolated from patients in selected hospitals in the Ashanti Region of Ghana. Antibiograms of the isolates were determined using the Kirby-Bauer disk diffusion method. Antibiotic resistance genes (mecA and mecC) were detected and efflux pump activity assessed using polymerase chain reaction (PCR) and microbroth dilution methods, respectively.
Results: Out of 626 samples obtained from patients, S. aureus was identified in 68, representing 10.9%. Multidrug resistance (MDR) was observed in 46 (67.6%) of the S. aureus isolates of which 28 (60.9%) were Methicillin Resistant Staphylococcus aureus (MRSA). The MRSA isolates showed higher susceptibility to trimethoprim-sulfamethoxazole (50%) and higher resistance to oxacillin and cefoxitin (100%). mecA gene was identified in 9 (32.1%) of the MRSA isolates whereas mecC gene was absent in all the isolates. The isolates did not exhibit any multiple efflux pump activities.
Conclusion: The prevalence of MDR-MRSA in S. aureus infections at healthcare facilities in the Ashanti region was found to be high. The presence of the mecA gene was identified as a possible mechanism responsible for resistance in the MRSA isolates.