Susceptibility of nonictalurid fishes to experimental infection with Edwardsieiia ictalun

Abstract

Studies were conducted to determine the potential pathogenicity of Edwardsiella ictaluri to economically important nonictalurid fishes in California, USA. White sturgeon Ac~penser transmontanus, striped bass Morone saxatilis, and chinook salmon Oncorhynchus tshawytscha were immersionchallenged in parallel with channel catfish Ictalurus punctatus. During a 14 d period, chlnook salmon and channel catfish succumbed to ~nfechons with E, ictalun but the other species did not. An immersion exposure to 4.0 and 7.9 X 10' cfu rill-' of E. ictalun for 30 S resulted in a 92 and 48 % mortality among chinook salmon and rainbow trout 0 . mykiss, respectively. A Gram-negahve septicemia occurred m infected fishes, and pure cultures of E. ictaluri were recovered from dead and surviving fish. There was a moderate to severe necrosis of the Liver and kidney in both salmonids and channel catfish. Intracellular bacteria occurred within mononuclear Inflammatory cells and hepatocytes. These results suggest that E. ictaluri is a potential pathogen of salmonid fishes.

Mortality and pathology in brown bullheads Amieurus nebulosus associated with a spontaneous Edwardsiella ictaluri outbreak under tank culture conditions

“…All of the brown bullheads from the present case exhibited generally severe renal damage. The pathological changes in the kidney were more like those described in association with E. ictaluri infection in Chinook salmon (Baxa et al 1990). …”

“…In addition to ictalurids, this organism has also been isolated from moribund green knifefish Eigenmannia virescens, cultured eels Anguilla japonica, the Bengal danio Danio devario and blue tilapia Tilapia aurea (Kent & Lyons 1982, Chung & Kou 1987. Efforts to produce the disease in commonly cultured species including largemouth bass Micropterus salmoides, bighead carp Aristichthys nobilis, golden shiner Notemigonus crysoleucas, and white sturgeon Acipenser transmontanus have been unsuccessful (Plumb & Sanchez 1983, Baxa et al 1990). …”

Virulence of Aeromonas hydrophita and some other bacteria isolated from European eels Anguilla anguilla reared in fresh water

“…Fish were exposed to 107 and to 108 cells ml-l during each treatment. Mortalities were recorded daily for 14 d (Baxa et al 1990). Samples from ulcers, livers, and kidneys of freshly dead elvers were examined for the presence of the challenge bacterium.…”

First detection of Edwardsiella ictaluri (Proteobacteria: Enterobacteriaceae) in wild Australian catfish

“…Salmonids (principally O. mykiss and Salmo salar L.) and barramundi, Lates calcarifer (Bloch), are among the most valuable cultured finfish species (Stephan & Hobsbawn, ). Lates calcarifer and numerous salmonid species are susceptible to E. ictaluri (Baxa et al., ; Gibson‐Kueh, Crumlish, & Ferguson, ; Keskin et al., ).…”

“…Edwardsiella ictaluri has been isolated from seven families of catfish (Ictaluridae, Bagridae, Clariidae, Pangasiidae, Siluridae, Plotosidae and Ariidae) (Crumlish, Dung, Turnbull, Ngoc, & Ferguson, ; Geng et al., ; Kasornchandra, Rogers, & Plumb, ; OIE ; Shotts et al., ; Ye, Li, Qiao, & Li, ) and from an increasing number of non‐catfish species throughout the world (Baxa, Groff, Wishkovsky, & Hedrick, ; Hawke et al., ; Kent & Lyons, ; Keskin, Secer, Izgur, Turkyilmaz, & Mkakosya, ; Sakai et al., ; Soto et al., ; Waltman, Shotts, & Blazer, ). It appears to be a host generalist, although several non‐catfish species have been found to be resistant to experimental infections (Plumb & Sanchez, ).…”