also known as: fish gangrene, edwardsiellosis, emphysematous putrefactive disease of catfish, red disease
Edwardsiella tarda, named after P. R. Edwards, is a Gram-negative bacillus bacterium which belongs to the Enterobacteriaceae family. The organism has flagella ('tails') and is a motile facultative anaerobe. E. tarda is a pathogen of both humans and freshwater fish. The pathogen is a threat to aquaculture and the fishing industry, especially fish farms. It is found predominantly in freshwater environments colonizing the guts of fish. Common clinical signs include organomegaly, ocular disease, rectal prolapse, ecchymosis, and especially hemorrhagic septicemia.