魚類由来ビブリオが産生するニジマスおよびマウス致死毒

Abstract

The biological activities of cell-free culture filtrates of three pathogenic strains of Vibrio commonly associated with vibriosis in fish (V. anguillarum NCMB6 and NCMB571 strains, and Vibrio sp. N7802 strain) were examined to determine their relations to the pathogenesis. Extracellular materials from culture filtrates of NCMB571 and N7802 strains separated by DEAE-cellulose chromatography followed by Sephadex G200 chromatography showed lethal toxicity for rainbow trouts and mice. Cytopathogenicity was observed in CHSE-214 chinook salmon embryo-derived cell line inoculated with culture filtrate of NCMB571 strain. NCMB6 and NCMB571 strains produced hemolysin against erythrocytes of eleven animal species, including fish. Hemolysin of NCMB571 strain was thermolabile, but toxic material was comparatively thermostable. These strains of Vibrio also produced alkaline proteolytic enzyme. On the contrary, N7802 strain was found to be a poor producer of both hemolysin and protease. These results indicated that the extracellular products, such as toxic material, hemolysin and protease, produced by Vibrio may be responsible for pathogenesis of vibriosis in fish. However, the lethal toxicity of culture filtrate of N7802 strain did not seem to be related to hemolysin or protease.