Author(s): S. Balachandar*, R. Dhanabalan, A. Manikandan and R. Rajendran
The in vitro antimicrobial activity of chitosan was investigated against the bacterial isolates of E. coli, K. pneumoniae, E. faecalis, P. aeruginosa, Salmonella enterica subsp. enterica serovar typhi and S. dysenteriae using disc diffusion method. The highest tested concentration of 400 µg/ml of chitosan had a good potential of antibacterial activities (inhibition diameter ranged from 07-13 mm) against all the tested organisms. Highest antibacterial activity was found against E. coli and the lowest activity was found against E. faecalis. The results revealed that, the inhibitory effects of chitosan differed depending on the types of the tested bacteria. The MIC range observed for chitosan was from 8 mg/ml to 32 mg/ml with the lowest MIC value was observed against E. coli and K. pneumoniae. The MBC values observed were in the range from 32 to 128 mg/ml and the lowest MBC value with highest antibacterial activity was observed against E. coli and Salmonella enterica subsp. enterica serovar typhi. In conclusion, chitosan could be promising natural antimicrobial agent with potential applications in controlling bacterial contaminants of water.