Pathogenicity of Vibrio harveyi to black rockfish, Sebastes schlegeli

Department of Aquatic Life Medicine, Pukyong National University, Busan 608-737, KoreaVibrio harveyi, one of the major causal agent of vibriosis, affects a diverse range of marine vertebratesand invertebrates over a wide geographical area. The organism is synonymous with Vibrio carchariae,which is also known as a fish pathogen. The aims of this study were to investigate the characteristics of thepathogenic non-luminous V. harveyi and the luminous V. harveyi. And V. harveyi isolates were examinedthe pathogenicity to the black rockfish, Sebastes schlegeli. Both strains of V. harveyi showed haemolyticactivity, and the survival rate of non-luminous V. harveyi FR 2 was higher than other strains in the skin, gutmucus and fresh serum of olive flounder, Paralichthys olivaceus and black rockfish, Sebastes schlegeli,respectively. The virulence of non-luminous V. harveyi FR 2 was higher than that of luminous V. harveyiVIB 391 in the intraperitoneally infected black rockfish. In conclusion, the present study revealed that thepathogenicity of V. harveyi FR 2 isolated from marine fish was higher than that of V. harveyi VIB 391 iso-lated from shrimp for black rockfish. It was suggested that the pathogenicity of V. harveyi on the blackrockfish was related with bacterial luminescense.Key words: Vibrio harveyi, Pathogenicity, Black rockfishVibrio harveyi는1980년대부터새우양식장이밀집해있는인도네시아 (Sunaryanto et al.,1986), 필리핀(Lavilla-Pitogo et al., 1990) 및대만(Liu et al., 1996) 등에서새우류의대량폐사를야기하는병원성세균으로잘알려져있다(Karunasagar et al., 1994; Pizzutto and Hirst, 1995;Robertson et al., 1998; Vandenberghe et al., 1998).특히, larvae와post-larvae에감염되면폐사율이100 %에달하며이들은luminescence 양성세균으로중감염된새우는형광을나타내는특징이있어luminous vibriosis로잘알려져있다(Sunaryanto et al., 1986; Lavilla-Pitogo et al., 1990;Vandenberghe et al., 1998). 그러나, 1990년대후반에들어서면서새우류뿐아니라여러해수어류에도 감염된다는 보고가 늘고 있어(Kraxberger-Beatty et al., 1990; Ishimaru andMuroga, 1997; Alvarez et al., 1998), 다양한어종에서대량폐사를유발하는것으로보인다. 한편여러해수어류에감염되는 V. harveyi는새우에서질병을일으키는 luminescence 양성세균이