Edwardsiella tarda is a member of the family Hafniaceae. The bacterium is a facultatively anaerobic, small, motile, gram negative, straight rod with flagella. Infection causes Edwardsiella septicemia (also known as ES, edwardsiellosis, emphysematous putrefactive disease of catfish, fish gangrene, and red disease) in channel catfish, eels, and flounder. Edwardsiella tarda is also found in largemouth bass and freshwater species such as rainbow trout. It is a zoonosis and can infect a variety of animals including fish, amphibians, reptiles, and mammals. Edwardsiella tarda has also been the cause of periodic infections for various animals within zoos. E. tarda has a worldwide distribution and can be found in pond water, mud, and the intestine of fish and other marine animals. It is spread by c