Serotype and Siderophore Production of Edwardsiella tarda Isolated from Water at Eel Farms

Appearance of Edwardsiella tarda were monitored in pond water culturing eel Anguilla japonica in Kagoshima prefecture. E. tarda were isolated at almost all sampling times. Serotype and siderophore production of the E. tarda isolates, which are involved with its pathogenesis, were determined. Out of 370 isolates, 194 isolates (52%) were classified into serotype A and 246 isolates (66%) produced siderophore. Ninety-one percent of the isolates that were classified into serotype A produced siderophore;72%of those that produced siderophore were classified into serotype A. There was no cross linkage between serotype and siderophore production in E. tarda.