Comparative Evaluation of the Effect of Annona muricata (Graviola) Leaves Extracts and Cefoxitin on Staphylococcus aureus

Resistance of Staphylococcus aureus to beta- lactam drugs most especially cefoxitin is a known global problem. Current researches are geared toward evaluating the antimicrobial properties of medicinal plants against these organisms. This study was aimed at comparatively evaluating the antimicrobial effects of cefoxitin and Anonna muricata (Graviola) against Staphylococcus aureus strains. A total of ten Staphylococcus aureus strains obtained from the Microbiology Department of General Hospital were subjected to susceptibility testing against cefoxitin and Anonna muricata extracts (both aqueous and ethanol), respectively using standard microbiology techniques. Out of the 10 isolates tested, 4 (40%) showed resistance to cefoxitin, 2 (20%) were intermediate while 4 (40%) showed susceptibility. However, 8 (80%) out of 10 isolates showed susceptibility to Annona muricata ethanol extract while 2 (20%) were resistance. In addition, 9 (90%) out of the 10 isolates showed resistance to Anonna muricata aqueous extracts. This study reveals that the isolates of Staphylococcus aureus were significantly more susceptible to alcohol extract of A. muricata than to cefoxitin consistently at concentration of 500-800 mg. There is a need for further studies aimed at evaluating its potentials against other isolates.