Characterization of Vibrio viscosus and Vibrio wodanis isolated at different geographical locations: a proposal for reclassification of Vibrio viscosus as Moritella viscosa comb. nov.

Vibrio viscosus and Vibrio wodanis are recently described species of psychr otropic bacteria that have been found associated with a disease called 'win ter ulcer', affecting salmonid fish reared in saline water in Norway. Icela nd and recently in scotland. V. viscosus and V. wodanis strains initially i solated from fish in Iceland and Norway were subjected to characterization using biochemical tests, SDS-PAGE of whole-cell proteins and a novel DNA fi ngerprinting method, amplified fragment length polymorphism (AFLP), The V v iscosus strains isolated from diseased fish grouped into homogeneous subgro ups according to geographical origin and challenge experiments revealed tha t representatives of these groups are virulent. The results revealed that t he V. wodanis strains are heterogeneous genotypically and phenotypically. S equencing of almost complete 16S rRNA genes of V, viscosus and V. wodanis r evealed that V. viscosus showed a 99.1% sequence similarity to Moritella ma rina and V. wodanis showed a 98.8% sequence similarity to Vibrio logei CIP 103204. A reclassification of Vibrio viscosus as Moritella viscosa comb. no v. is proposed.