1Zumbi, C. N., 2Odoi, H., *1Boamah, V. E., 1Boakye, Y. D., and 1Agyare, C.
1Pharmaceutical Microbiology Section, Department of Pharmaceutics, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
2Department of Pharmaceutical Microbiology, School of Pharmacy, University of Health and Allied Sciences, Ho, Ghana
*Correspondence to: etsiapa@yahoo.com; veboamah.pharm@knust.edu.gh;
Abstract:
Background: Globally, methicillin-resistant Staphylococcus aureus (MRSA) infections are associated with increased morbidity and mortality amongst patients; however, reports on MRSA infections in Ghana are mostly from tertiary healthcare facilities. This study determined the prevalence of methicillin and multiple efflux resistance mechanisms in S. aureus isolates from five selected primary and tertiary healthcare facilities in Ghana.
Methodology: Different clinical samples (nasal, urine and wound) were collected from patients in four primary and one tertiary hospitals in Ghana. Staphylococcus aureus was isolated on mannitol salt agar and preliminarily identified using conventional biochemical tests and confirmed by PCR amplification of Spa1113 gene and Matrix Assisted Laser Desorption Ionisation–Time of Flight Mass Spectrometry (MALDI-TOF). Antibiotic susceptibility test for each isolate to selected antibiotics was determined by the Kirby-Bauer disk diffusion method, and multi-drug resistance (MDR) was defined as resistance to three or more antibiotic classes. The mecA and mecC genes were detected by polymerase chain reaction (PCR). Multiple efflux-pump activity of multidrug resistant isolates was assessed against ampicillin and ciprofloxacin by microbroth dilution assay with reserpine, an efflux pump inhibitor.
Results: From a total of 626 clinical samples, S. aureus was confirmed in 68 (10.9%). MDR was detected in 46
(67.6%) of the 68 isolates, and 28 (41.2%) were phenotypic MRSA, with mecA gene confirmed in 9 (32.1%) of the MRSA isolates while mecC gene was absent in all the isolates. MRSA isolates were more susceptible to trimethoprimsulfamethoxazole (50.0%) compared to other selected antibiotics. Multiple efflux-pump activity was detected as contributing to resistance in 6 of 25 (24.0%) S. aureus isolates.
Conclusion: The high prevalence of MRSA in clinical samples mediated by mecA gene and possible efflux pump activity call for re-evaluation of treatment protocols of S. aureus infections at both primary and tertiary healthcare facilities in Ghana.
Key words: MRSA, mecA gene, mecC gene, Staphylococcus aureus, efflux-pump
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