Replication of Infectious Pancreatic Necrosis Virus in different cell lines and in rainbow trout (Oncorhynchus mykiss) fingerlings

Abstract

The results of a study of Infectious Pancreatic Necrosis Virus (IPNV) isolated in natural reservoirs in Ukraine are presented. The pathogenicity of isolates was investigated in vitro on cell cultures and in vivo on rainbow trout, Oncorhynchus mykiss (Walbaum), fingerlings. Experimental indications were that the Ukrainian IPNV isolates have affinity with reference European strains. During the reproduction of these isolates in cell cultures of FHM (fat head minnow), RTG-2 (rainbow trout gonads), and BF-2 (bluegill caudal peduncle), complicated degenerative changes were visible that finally led to the full destruction of cell monolayers. The experimental infection of rainbow trout fingerlings resulted in typical disease symptoms that were systemic. However, obvious evidence of viral infection was noted in single individuals only, and the majority of experimental fish died without visible disease symptoms. During the study of physicochemical properties, it was noted that Ukrainian isolates completely lost their infectivity with chloroform treatment and heating to 60°C. This proved that IPNV isolates are resistant to Ion concentrations in the range of pH 3.0 to 12.0.