Isolation and Preliminary Characterization of a Birnavirus from the Sole Solea Senegalensis in Southwest Spain

Abstract A group of wild broodstock of Senegalese sole Solea senegalensis was introduced into a culture facility in southwest Spain for endocrinological studies, and fish were kept under standard culture conditions. External signs of disease (dark coloration, hyperactivity, uncoordinated swimming and behavior) appeared suddenly, and the group experienced almost 100% mortality thereafter. The few survivors from this group, kept in a different facility, developed similar signs the next year. The cause of the disease was unclear, although viruslike structures were observed in ultrathin sections of kidney from one diseased fish, and it was possible to isolate a birnavirus from all the visceral and skin homogenates from this and other specimens inoculated onto samples of the CHSE-214 (chinook salmon embryo) cell line. Further serologic, phenotypic, and biochemical characterizations of the agent indicated its similarity to infectious pancreatic necrosis virus (IPNV). Western blot assays using the anti-IPNV mono...