Efficacy of Plukenetia conophora against Multidrug Resistant Staphylococcus aureus isolated from Wound

Abstract

Due to the increasing resistance of the superbug, Staphylococcus aureus, and many other pathogenic microorganisms to 
conventional antibiotics, there is a need to search for new and better antimicrobial substances. This study was carried out to 
evaluate the antimicrobial efficacy of the African walnut plant, Plukenetia conophora against antibiotic-resistant Staphylococcus 
aureus. 350 wound swab samples were obtained. Isolation, characterization, identification and antibiotic susceptibility testing 
of Staphylococcus aureus isolates were done using standard microbiological procedures. Antimicrobial activity screening of the 
different extracts on the antibiotic-resistant isolates was performed with the agar well diffusion technique. Varying concentrations 
(100mg/ml, 50mg/ml, 25mg/ml,12.5mg/ml) of both the aqueous and ethanol extracts of the leaves of the plant were assayed for 
antimicrobial potential and their antimicrobial activity was compared with the antibiotic, Nitrofurantoin 300µg (NIT) for each of 
the antibiotic-resistant Staphylococcus aureus isolates. Only the leaf extracts possessed antimicrobial potential against antibioticresistant Staphylococcus aureus. Also, ethanol extracts of the leaves displayed the higher antimicrobial potential of the leaf 
extracts is dose-dependent and is higher than that of NIT upon comparison. The MIC and the MBC were found to be 25mg/ml 
and 100 mg/ml respectively for both ethanol and aqueous leaf extracts. Flavonoids, alkaloids, tannins, and phenols were observed 
to be responsible for the antimicrobial potential of the leaves of Plukenetia conophora. This study reveals that the leaves of 
Plukenetia conophora possess antimicrobial property and as such can be used as an alternative to conventional antibiotics for the 
treatment of infections caused by multidrug-resistant Staphylococcus aureus.