Infectivity of aquabirnavirus strains to various marine fish species

To determine the infectivity of marine birnavirus (MABV) in various marine fish species, experimental infection was performed in combination groups of 5 fish species with 7 strains of MABV and 1 strain of infectious pancreati c necrosis virus (IPNV). Mortality was observed in yellowtail Seriola quinq ueradiata and amberjack S. dumerili infected with MABV strains Y-6, Y-10K a nd H-1, but not in other infected species. MABV was reisolated from most co mbination groups, but the virus isolation rate and virus infectivity titer were often significantly different among groups with the same fish species or with the same virus strain. All MABV strains replicated well in makogare i Limanda yokohamae, but only slightly in tiger puffer Takifugu rubripes. I PNV also replicated in all fish species without causing death. The isolatio n rate and infectivity titer of IPNV were similar to or higher than those o f non-virulent strains of MABV. In conclusion, the infectivity of MABV for different fish species is considered to change, which is an important facto r in the development of the infection cycle of this virus among marine orga nisms.