양식 넙치, Paralichthys olivaceus에서 분리한 Vibrio scophthalmi의 감염특성

Abstract

Recently high mortality of cultured olive flounder occurred frequently at the fish farms in Ulsan, Korea. The diseased fish showed skinny body and swimming behavior on the water surface with liver atrophy and white enteritis as internal signs. The isolated bacteria was identified to V. scophthalmi by biochemical test, nucleotide analysis of 16s rRNA and dnaJ gene sequencing. The pathogen of this study showed strong pathogenicity as 75% mortality to olive flounder by infection of 1 × 106 CFU/fish. The pathological sign of diseased fish was not different between the naturally diseased and the artificially infected fish. Histopathological change was shown to liver atrophy, desquamation of the intestinal mucosa and hyaline droplet like as other previous studies. V. scophthalmi showed some positive effects on the other bacteria growing during coculture and nurse culture test. It will be contributed to a cofactor as the mixed infection to olive flounder.