Tests for various virulence factors, such as production of haemolysin on sheep blood agar plate, cytotoxin on HeLacell line and enterotoxin inGM-1ELISAand suckling mouse assay model, were done among the various strains of Aeromonas spp., Vibrio spp., Plesiomonas shigelloides and Esch. coli isolated from fresh water fish samples. Invassive properties of the isolates were also seen by using Sereny test…