Distribution of Methicillin-Resistant Staphylococcus aureus (MRSA) in Apparently Healthy Population and its Susceptibility to Saponins from Dialium guineense

Abstract

Aims: The ethanolic extracts of stem bark and fruit pulp as well as saponins from Dialium guineense were assayed for antibacterial activity against Gram positive and negative strains and clinical strains of methicilin resistant Staphylococcus aureus (MRSA) isolated from different locations on human body aged 20-30 years within the University of Nigeria community. Methodology: Agar diffusion technique was adopted. Results: The results showed that MRSA is predominant in apparently healthy population of the University community with 100% in males and 92.3% females showing positive case in nasal swab, 87.5% and 96.6 % positive from ear swabs of male and female volunteers respectively; and 77.7% positive from the high vaginal swabs of females. MRSA and other clinical isolates showed higher susceptibility to saponins compared to crude extracts; however, Bacillus cereus (NRRL 14724 and 14725) were not susceptible to the saponins from D. guineense. The MICs of the saponins were 31.25 mg/mL (B. subtilis ATCC 6051, P. aeruginosa, S. typhi, S. knitambo, P. mirabilis and S. aureus), 62.50 mg/mL (E. coli) and 125 mg/mL (P. aeruginosa ATCC 10145). Comparable MICs of higher values were obtained with the crude ethanolic extracts of stem bark and fruit pulp against MRSA and clinical isolates. Conclusion: The present findings revealed wide distribution of MRSA in an apparently healthy population in Nigeria and the susceptibility patterns showed the presence of a broad spectrum antibacterial agent in D. guineense.