Antimicrobial Potentials of Eclipta Alba by Well Diffusion Method

The susceptibility of nine microbial species to an antimicrobial extract from Eclipta alba was screened using the well diffusion assay. Three different volumes (24, 30 and 36 μl/well) were tested. Analysis of the data revealed that all extracts from Eclipta alba showed antimicrobial activities. An N-butanol fraction showed inhibitory activities against all nine microbial species. Samples extracted with petroleum ether, dichloromethane, methanol or water had varying levels of inhibition against some of these microorganisms. The most resistant microbial strain was Salmonella typhi when tested against petroleum ether, dichloromethane, methanol and water extracted samples. The most susceptible Gram-positive bacterium was Bacillus subtilis, which was inhibited by all six extracts from Eclipta alba, while the most resistant Grampositive bacterium was Bacillus cereus. Erwinia carotovora was the most susceptible Gram-negative bacterium, while Salmonella typhi and Escherichia coli were highly resistant among the Gram-negative bacteria.