First case of Edwardsiella ictaluri infection in China farmed yellow catfish Pelteobagrus fulvidraco

The first epizootic of yellow catfish Pelteobagrus fulvidraco (10 g–250 g) caused by Edwardsiella ictaluri, is described. Bacteria were isolated from yellow catfish, P. fulvidraco, kept in a pond in China. During the outbreak, the cumulative mortality was up to 50%. Acute disease was characterized grossly by cutaneous hemorrhage, ulceration and enteritis, while chronic disease a soft, fluctuant red swelling on the dorsum of the head. Brain, liver, kidney and spleen of diseased fish, were aseptically streaked on Trypticase Soy Agar, respectively. After incubation, pure cultured colonies were observed and biochemically characterized with biochemical tests. A further phylogenetical (16S rDNA) characterization identified it as E. ictaluri. To our knowledge, this is the first report on the E. ictaluri infection in yellow catfish.