Antimicrobial properties of tropical plants against 12 pathogenic bacteria isolated from aquatic organisms

Disk diffusion technique was used to determine the antibacterial activity of aqueous and methanolic extracts of edible tropical plant against 12 clinical and pathogenic bacterial strains isolated from aquatic animals. They were Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio vulnificus, Vibrio cholerae, Escherichia coli, Citrobacter freundii, Edwardsiella tarda, Aeromonas hydrophilla, Salmonella sp., Schewanella putrifaciens and Streptococcus sp. The zone of inhibition varies depending on bacterial species and type of extract. The average diameter of inhibition zones ranges from without inhibition zone to 12 mm and without inhibition zone to 11 mm for water and methanolic extract, respectively. All the 9 plants tested showed antimicrobial activity against one or more species of bacteria. The most active antimicrobial plants were Colocasia esculenta, Citrus microcarpa, Centella asiatica and Morinda citrifolia