Abstract

The aqueous ethanol and acetone-ethanolic extracts of Vernonia amygdalina leaves and stems were investigated for their antimicrobial activities compared to ciprofloxacin, againstEscherichia coli, Klebsiella sp and Staphylococcus sp. The antimicrobial activity of each extract on the isolates was determined by agar well diffusion and minimum inhibitory concentration methods. The acetone-ethanolic extract of the leaf showed the highest antibacterial activity on Klebsiella sp in both methods used, followed by the ethanol leaf extracts on the same organism. E. coli and Staphylococcus sp were not susceptible to any of the extracts even at higher concentrations. The aqueous extracts of both leaf and stem were ineffective on all the test isolates at all concentration. Comparatively, the test isolates were sensitive to ciprofloxacin in both methods used but the antibacterial effect of acetone-ethanolic leaf extract on Klebsiella sp was higher than that of ciprofloxacin onKlebsiella sp. The results from this research showed that V. amygdalina could be used as raw material in the synthesis of antimicrobial drugs, especially against Klebsiella sp which have been attributed with high level drug resistance in urinary tract infections.

Key words: Ciprofloxacin, acetone, urinary tract infections, ethanol.