Streptococcosis in aquarium fish

Abstract

Streptococcus-like bacteria were recovered In large numbers from moribund zebra danlos Brachydanio rerio and pearl danios Brachydanio albohneatus imported Into Canada as aquarium species. Histopathology revealed a bacteremia with lesions present in many organs, but in particular the spleen and k~d n e y .These could best be characterized as acute and necrotizlng rather than granulomatous Similar dlsease was subsequently produced experimentally in zebra danios as well as In rainbow trout Oncorhynchus mykiss and white cloud mountain minnows Tanichthys albonubes, by means of bath immersion. In these experiments, mortality started 2 to 4 d after exposure.

Pathological changes in cultured channel catfish Ictalurus punctatus spontaneously infected with Streptococcus iniae

“…The latter was consistent with the clinical symptoms, since meningitis can result in erratic swimming (Chang & Plumb 1996). The severe splenitis may be due to the high capability of the spleen to trap bacteria, because streptococci can be commonly observed in this organ in conjunction with tissue necrosis (Ferguson et al 1994, Perera et al 1998). These observations indicate that S. iniae can cause a systemic infection associated with a strong inflammatory response in the host, which is in accordance with reports in other species of fish (Perera et al 1998, Soltani et al 2005, Russo et al 2006).…”

Isolation and characterization of Streptococcus dysgalactiae from diseased Acipenser schrenckii

“…The course of this streptococcosis was relatively chronical in experimental infections since there was no mortality in the first 24 h, and so were natural infections of sturgeon. In contrast, it was reported in many studies (Ferguson et al, 1994;Zhou et al, 2007) that streptococcosis caused acute and prompt mortality of fish. Although there were weak congestion on the anus and at the base of pectoral fins as well as no appearance of tumid and colorful liver in artificial challenge trials, symptoms of Amur sturgeon in experimental infections were ultimately similar to those of diseased sturgeon in natural infections since there were main symptoms in common-swollen abdomen with much fluid in it and hemorrhage on the intestinal wall, and pale gills in some cases.…”

Streptococcal infections of farmed fish

“…In Spain, isolated outbreaks have been reported in coastal turbot culture (Toranzo et al 1995 involving two strains Streptococcus parauberis and an Enterococcus -like bacterium which resembles Enterococcus serìolicida (Toranzo et al 1995Domenech et al 1996. In Canada, human disease was associated with handling of farmed Atlantic salmon (Weinstein et al 1997) and strains from fish were also isolated (Ferguson et al 1994). The disease has also been reported from Australia, South Africa and Saudi Arabia (Alharbi 1994).…”