Abstract

Thirty four medicinal plants, belonging to twenty eight different families, were screened for potential antibacterial activity against six bacterial strains belonging to Enterobacteriaceae, viz.Enterobacter aerogenes ATCC13048, Escherichia coli ATCC25922, Klebsiella pneumoniae NCIM2719, Proteus mirabilis NCIM 2241, Proteus vulgaris NCTC8313,and Salmonella typhimurium ATCC23564. Antibacterial activity of aqueous and alcoholic extracts was tested by the agar disc diffusion and agar well diffusion methods. The ethanol/methanol extracts were more active than aqueous extracts for all the plants studied. The most susceptible bacterium was K. pneumoniae, while the most resistant bacteria were S. typhimurium and E. coli. From the screening experiment, Woodfordia fruticosa Kurz.showed best antibacterial activity. Hence, this plant may be used further to isolate and evaluate the therapeutic antimicrobials.

Key words: Medicinal plants, antibacterial activity, aqueous extracts, alcoholic extracts, Enterobacteriaceae