A cross-sectional study on the prevalence and drug susceptibility pattern of methicillin-resistant Staphylococcus aureus isolated from patients in the Buea Health District, Cameroon

INTRODUCTION: Staphylococcus aureus, which is part of the normal flora accounts for most acute and chronic infections in humans, and treatment options are greatly limited, when infection is caused by methicillin-resistant Staphylococcus aureus (MRSA). This study was to determine the prevalence and antimicrobial susceptibility pattern of MRSA from clinical samples obtained randomly from patients in Buea Health District. METHODS: a total of 264 wounds, nasopharynx, and urine samples were collected from patients from different hospitals in Buea and transported to the laboratory in the University of Buea, for analysis. Samples were inoculated on mannitol salt agar for S. aureus isolation, characterized morphologically by gram staining and biochemically by catalase, coagulase, and hemolysis tests. Diagnosis of S. aureus was confirmed by molecular identification of the nuc gene. MRSA was identified from S. aureus by oxacillin screening and confirmed by molecular identification of the mecA gene. The data were analyzed using SPSS version 17.0. RESULTS: S. aureus was isolated from 70 (26.52%) and all were confirmed molecularly by nuc gene amplification. MRSA by oxacillin screening was 36 (13.64%) while MRSA detected by mecA gene amplification was 34 (12.88%). Antimicrobial susceptibility testing revealed 100% resistance to ampicillin, 88.24% to cefixime and 70.59% to ceftriaxone while low resistance was observed to meropenem (11.76%), doxycycline (14.71%), and vancomycin (17.67%). CONCLUSION: MRSA isolated from Buea Health District are resistant to ampicillin, cefixime, and ceftriaxone. The antimicrobials (meropenem, doxycycline, and vancomycin) should be used to treat MRSA infections in Buea Health District.