RESUMO
The aqueous and ethanolic extracts of Acorus calamus was evaluated for antibacterial activity against clinically important bacteria viz.. Bacillus subtilis (MTCC 441), Staphylococcus aureus (MTCC 96), Escherichia coli (MTCC 443), Proteus mirabilis (MTCC 1429), Pseudomonas aeruginosa (MTCC 424). The in-vitro antibacterial activity was performed by agar well diffusion method. The ethanolic extracts of A. calamus was active against all the investigated bacterial strains while aqueous extract was totally inactive against the studied gram negative bacterial strains (E. coli, P. mirabilis and P. aeruginosa) and showed moderate antibacterial activity against gram positive bacteria B. subtilis and Stap. aureus only at high concentration (200ml). However, further works are needed to identify the chemical nature of the active substances as well as their modes of actions on the bacterial cells and their roles in disease curing.