Abstract

The antimicrobial effects Ethanolic extracts of leaves of two species of genusZiziphus were determined against Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, Aspergillus niger and Candida albicans. S. pyogeneswas the most susceptible followed by E. coli while S. aureus was the least susceptible. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were 1 mg, 5 mg ml^-1 and 20 mg, 40 mg ml^-1, respectively. Extracts showed no activity against the fungal isolates - A. niger and C. albicans. The plants cannot be used in treating any type of fungal infections (dermatophycoses). The phytochemicals identified were cardiac glycosides, polyphenols, saponins and tannins. Extracts from these plants could be useful in the treatment of nosocomial infections, opportunistic infection of the unary tract (UTI), infantile gastroenteritis, travelers’ diarrhea, wound infection, meningitis, and wounds infection which are diseases caused by some of these organisms.

Key words: Antimicrobial activity, pathogenic microbes, phytochemical constituents, Ziziphus.