Virulence of Viral Hemorrhagic Septicemia Virus (VHSV) Isolates from Japanese Flounder Paralichthys olivaceus in Rainbow Trout and Several Species of Marine Fish

Two Japanese isolates of viral hemorrhagic septicemia virus (VHSV), JF00Ehi1 (Genogroup I) and KRRV-9601 (Genogroup III), from Japanese flounder Paralichthys olivaceus were examined for the virulence to rainbow trout Oncorhynchus mykiss and 4 species of marine fish. Rainbow trout injected intraperitoneally with each isolate at a dose of 107.5 TCID50/fish showed neither death nor hemorrhage in the skeletal muscle, while the mortalities in Japanese flounder were both 100%. The mortalities by intramuscular injection with JF00Ehi1 at a dose of 107.0 TCID50/fish were 95.0%, 75.0% and 97.5% in black rockfish Sebastes inermis, red sea bream Pagrus major and yellowtail Seriola quinqueradiata, respectively.