US Fish & Wildlife Service


Date of this Version



Published by UNITED STATES DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Division of Fishery Research Washington, D.C. 20240


The genus Edwardsiella was suggested by Ewing et al. (1965) to encompass a group of enteric bacteria generally described under vernacular names such as paracolon. The type species is E. tarda, which is an opportunistic pathogen of many animals. Meyer and Bullock (1973) reported E. tarda as a pathogen of channel catfish (Ictalurus punctatus) and named the disease emphysematous putrefactive disease of catfish. However, the organism described by Hoshina (1962) as the fish pathogen Paracolobactrum anguillimortiferum is now recognized as being E. tarda (Wakabayashi and Egusa 1973). Hawke (1979) isolated several strains of a bacterium closely resembling E. tarda from diseased cultured channel catfish, but later research showed it to be a distinct new species named E. ictaluri (Hawke et al. 1981). Accordingly, the name applied to E. ictalurus infections in catfish is enteric septicemia.