Antimicrobial effect of some Egyptian plants

Twenty eight crude water extracts of four Egyptian plants: Hibiscus sabdariffa (Karkade) , Tamarindus indica (Tamarind) t Glycyrrhiza glabra (Liquorice) and Ceratonia siliqua (Carob) , were tested for their antibacterial activities against 10 common pathogenic bacteria,Bacillus cereus, Shigella flexenary and Escherichia coli showed sensitivity to the 28 extracts. Shigella sp. showed sensitivity to 24 extracts while Pseudomonas sp. and Salmonella typhimurium were sensitive to 23 extracts. Salmonella paratyphi and Aerobacter aerogenes showed sensitivity to 22 extracts, Serratia marcesence and Aeromonas hydrophila showed sensitivity to 20 extracts. Karkade exhibited marked antibacterial activity against all the 10 organisms. E. coli and Shigella flexenary had no observed sensitivity to Liquorice extracts. Aerobacter aerogenes was the only one which had no observed sensitivity to Tamarind extracts. All the extracts of Carob were effective against only two pathogens:Bacillus cereus and Shigella flexenary. The results support the traditional uses of extracts of these plants for the management of bacterial infections and for the development of antibacterial agents for the preservation of foods.