Vibrio trachuri sp. nov., a new species isolated from diseased Japanese horse mackerel.

A new species, Vibrio trachuri sp. nov., was isolated from the cultured Japanese horse mackerel (Trachurus japonicus). These Vibrio were Gram negative, motile rods and formed yellow colonies on BTB teepol and TCBS plate, turned TSI medium to yellow and was sensitive to 150 μM O/129 (2,4-diamino-6,7-diisopropyl pteridine phosphate) like Listonella anguillarum which has been described as Vibrio anguillarum. However, the results of VP test and decarboxylation of lysine or dihydrolation of arginine suggested that these Vibrio are rather closely related to V. parahaemolyticus. DNA similarity determined by the microplate hybridization technique revealed that these Vibrio are genetically quite distant from Listonella anguillarum or V. parahaemolyticus and rather close to V. harveyi, although there was no Vibrio species which had more than 70% similarity value. From these results we propose to nominate Vibrio trachuri sp. nov. for this new Vibrio species.