Antibacterial Activity of Ginger (Zingiber officinale) Roscoe and Garlic (Allium sativum L.) Extracts on Escherichia coli and Salmonella typhi

摘要

The antibacterial activity of the ethanolic extracts of garlic and ginger against E.coli and S. typhi were positive. Though the growth inhibitory response varied with thetype of bacterial species tested and the type of extract. Ethanolic extract of ginger inhibited E. coli showing 9.00 mm diameter while S. typhi was inhibited w ith 10.00 mm diameter. The aqueous extract of garlic had no inhibitory effect on the two test organisms, but the aqueous extract of ginger inhibited S. typhi showing 8.0 mm diameter. Only the paper disc diffusion method was used and it gave clear zones of inhibition. In determination of minimum inhibitory concentration (MIC), it was observed that the range was between 75 mg mL 1 and 250 mg mL 1 of the concentrations. At any dilution below 75 mg mL 1 concentration, there was no growth inhibition by any extract. The results indicated that the aqueous extract had little or no inhibition while ethanolic extracts had a higher inhibitory effect in vitro against specific bacteria, E. coli and S. typhi, confirming their use in folk medicine.