The first isolation of a rhabdovirus from perch (Perca fluviatilis) in Norway

A rhabdovirus was isolated from perch (Perca fluviatilis) harvested from la ke Arungen in the South-Eastern part of Norway. The fish were placed in ind oor tanks for reproduction studies. A few days after the introduction, fish showed swimming disturbancies and lethargy, and a low mortality was observ ed during a period of several months. No gross or histopathological changes were observed. The virus was isolated from moribund fish in BF-2 cells. An extensive cytopathic effect (CPE) was observed, and examination of infecte d cell cultures by electron microscopy demonstrated virus particles with a morphology consistent with that of rhabdoviruses. The viral genome consists of RNA as shown by using specific metabolic inhibitors. The virus was furt her characterized by immunofluorescence (IF) and a plaque neutralization te st using a panel of different antisera against several fish rhabdoviruses. The virus was stained in IF with rabbit antisera against perch rhabdovirus, pike rhabdovirus and lake trout rhabdovirus and neutralised by anti perch rhabdovirus indicating that the Norwegian perch virus is closely related to these viruses belonging to the Vesiculovirus genus of the family Rhabdovir idae. This is the first time a rhabdovirus has been detected in perch in No rway, and it indicates that viruses belonging to this group might be more w idespread in nature than previously assumed.