Pathogenicity of a Rainbow Trout Isolate RtNa-0010 of Oncorhynchus masou virus (Salmonid herpesvirus 2) in Salmonid and Cyprinid Fish

Abstract

Pathogenicity of a rainbow trout isolate RtNa-0010 of Oncorhynchus masou virus (OMV = salmonid herpesvirus 2) was investigated in salmonids and cyprinids. Immersion method was used to challenge three species of salmonid fish with RtNa-0010 and OMV reference strain OO-7812 at a dose of 100 TCID₅₀/mL for 60 min. Cumulative mortality of rainbow trout was 3 and 51 of 51 fish when challenged with OO-7812 and RtNa-0010 respectively. When six salmonids and three cyprinids were challenged with RtNa-0010 (10³ TCID₅₀/fish) by intraperitoneal injection, mortality rates were 85%, 10% and 0% for rainbow trout, whitefish Coregonus lavaretus maraena and other tested fish respectively.