Vernonia amygdalina (Bitterleaf), Eucalyptus citriodora (Eucalypt) and Phyllanthus amarus (Schum) were investigated for their antibacterial properties against pure cultures of clinical isolates of Escherichia coli, Klebsiella sp., Salmonella sp. and Shigella sp. The isolates were obtained from dept of Medical Microbiology and Parasitology of the University of Ilorin Teaching Hospital. Water and Ethanol were used in the crude extractions of the active constituents of the plants. Broth dilution and Agar diffusion methods were used in determining the antibacterial effects of the different plant extracts on the test organisms. The minimum inhibitory concentration (MIC) of the water extracts on the test organisms was 50 mg/ml while that of the ethanolic extract ranged between 6.25 - 50 mg/ml. Similarly the diameters of zones of inhibition of the plant extracts at concentration of 100 mg/ml ranged between 3.0-14.0 mm and 3.0-18.0 mm for the water and ethanolic extracts respectively on the test organisms. Water extracts of vernonia amygdalina (Bitterleaf) and Schum (Phyllanthus amarus) were not effective on majority of the test organisms. Klebsiella sp. was not inhibited by the water extracts at the test concentrations. The Ethanolic extracts of Eucalyptus citriodora (Eucalypt) were most effective on all the test organisms. The least and the most susceptible organisms to the extracts were Shigella sp. and E. coli respectively. The results of this study suggest the possibility of using the ethanolic extracts of these plants in treating diseases caused by the test organisms.
Sule, I. O. and Agbabiaka, T. O.
"Antibacterial Effect of Some Plant Extracts on Selected Enterobacteriaceae,"
Ethnobotanical Leaflets: Vol. 2008
, Article 137.
Available at: http://opensiuc.lib.siu.edu/ebl/vol2008/iss1/137