Antibacterial Activity of Some Plants on Selected Clinical Isolates

An investigation was conducted on the antibacterial properties of extracts from four plants Anogeissus leiocarpus Terminalia glaucescens Adasonia digitata and Lennea welwitschii on the growth of Escherichia coli Staphylococcus aureus Salmonella typhii and Shegella dysentriae. The efficacy of the extracts was assessed by measuring the diameter of zone of inhibition around the colonies on nutrient agar medium. The result obtained showed that the root extracts from T.glaucescens and A.leiocarpus were active againts all the test bacteria. The ethanol and acqueous extracts of A.digitata did not exert any inhibitory effect on test organisms while the other eight extracts exhibited variable antibacterial activity. The minimum ihibitory concentration of the most active extracts ranged from 0.625 mg/ml to 5.0 mg/ml while the minimum bactericidal concentration was between 125 mg/ml-10.0 mg/ml. Preliminary phytochemical screening of the medicinal plants revealed that they contain saponin tannin alkaloid and glycoside.