Characterization of Vibrio harveyi Isolated from Diseased Dotted Gizzard Shad Konosirus punctatus

Abstract

Mass mortality of dotted gizzard shad Konosirus punctatus occurred at the Otagawa River estuary in Hiroshima Prefecture in autumn of 2007. Gram-negative bacteria were purely isolated from the kidney and brain of moribund fish. Based on the results of conventional characterization tests and genetic analysis, the bacterial isolates were identified as Vibrio harveyi. Intraperitoneal injection experiments revealed that the bacterial isolates were highly pathogenic to ayu Plecoglossus altivelis and amago salmon Oncorhynchus masou ishikawae. These results suggest that V. harveyi infection was associated with the mass mortality of dotted gizzard shad in 2007.