Four closely related species, Vibrio fischeri, Vibrio logei, Vibrio salmonicida and Vibrio wodanis, form a clade within the family Vibrionaceae; the taxonomic status and phylogenetic position of this clade have remained ambiguous for many years. To resolve this ambiguity, we tested these species against other species of the Vibrionaceae for phylogenetic and phenotypic differences. Sequence identities for the 16S rRNA gene were ≥97.4 % among members of the V. fischeri group, but were ≤95.5 % for members of this group in comparison with type species of other genera of the Vibrionaceae (i.e. Photobacterium and Vibrio, with which they overlap in G+C content, and Enterovibrio, Grimontia and Salinivibrio, with which they do not overlap in G+C content). Combined analysis of the recA, rpoA, pyrH, gyrB and 16S rRNA gene sequences revealed that the species of the V. fischeri group form a tightly clustered clade, distinct from these other genera. Furthermore, phenotypic traits differentiated the V. fischeri group from other genera of the Vibrionaceae, and a panel of 13 biochemical tests discriminated members of the V. fischeri group from type strains of Photobacterium and Vibrio. These results indicate that the four species of the V. fischeri group represent a lineage within the Vibrionaceae that is distinct from other genera. We therefore propose their reclassification in a new genus, Aliivibrio gen. nov. Aliivibrio is composed of four species: Aliivibrio fischeri comb. nov. (the type species) (type strain ATCC 7744T =CAIM 329T =CCUG 13450T =CIP 103206T =DSM 507T =LMG 4414T =NCIMB 1281T), Aliivibrio logei comb. nov. (type strain ATCC 29985T =CCUG 20283T =CIP 104991T =NCIMB 2252T), Aliivibrio salmonicida comb. nov. (type strain ATCC 43839T =CIP 103166T =LMG 14010T =NCIMB 2262T) and Aliivibrio wodanis comb. nov. (type strain ATCC BAA-104T =NCIMB 13582T =LMG 24053T).

Aims:  To determine if infection of Vibrio harveyi with the V. harveyi myovirus‐like (VHML) bacteriophage causes a change to the phenotypic profile of this species. Methods and Results:  Using 46 biochemical and metabolic tests, phenotypic profiles for noninfected V. harveyi and VHML infected V. harveyi were developed. Comparison of the infected and bacteriophage‐infected strains of V. harveyi 645, 20 and 45 were found to have different test results for d‐gluconate utilization, γ‐glutamyl transpeptidase and sulfatase activity, respectively. Using probabilistic identification, VHML infected and noninfected strains were identified as V. harveyi and had similar Willcox probability scores though the modal likelihood scores were reduced for VHML infected strains. One VHML infected strain, 642b, was misidentified as V. campbellii by phenotyping but not by PCR. It would appear that the phenotype of V. harveyi strains infected with VHML, are sufficiently altered that they occur at the margins of the known range of strain variation for V. harveyi. Conclusion:  Infection of V. harveyi with VHML causes the phenotypic profile of the bacterium to change. This change reduces the modal likelihood score resulting in a poorer level of assurance for an identification of V. harveyi, especially in the natural host, strain 642. The bacteriophage VHML integrates into different sites in different strains of V. harveyi. Significance and Impact of the Study:  The identification of V. harveyi as the causative agent of mortality in aquatic organisms is predominantly achieved through phenotyping. Since bacteriophages alter virulence in V. harveyi, understanding the effect they have on phenotype is important.

Vibrio jasicida sp. nov., a member of the Harveyi clade, isolated from marine animals (packhorse lobster, abalone and Atlantic salmon) Six isolates of a facultatively anaerobic bacterium were recovered in culture from marine invertebrates and vertebrates, including packhorse lobster (Jasus verreauxi), abalone (Haliotis sp.) and Atlantic salmon (Salmo salar), between 1994 and 2002. The bacteria were Gramnegative, rod-shaped and motile by means of more than one polar flagellum, oxidase-positive, catalase-positive and able to grow in the presence of 0.5-8.0 % NaCl (optimum 3.0-6.0 %) and at 10-37 6C (optimum 25-30 6C). On the basis of 16S rRNA gene sequence analysis and multilocus sequence analysis (MLSA) using five loci (2443 bp; gyrB, pyrH, ftsZ, mreB and gapA), the closest phylogenetic neighbours of strain TCFB 0772 T were the type strains of Vibrio communis (99.8 and 94.6 % similarity, respectively), Vibrio owensii (99.8 and 94.1 %), Vibrio natriegens (99.4 and 88.8 %), Vibrio parahaemolyticus (99.4 and 90.3 %), Vibrio rotiferianus (99.2 and 94.4 %), Vibrio alginolyticus (99.1 and 89.3 %) and Vibrio campbellii (99.1 and 92.3 %). DNA-DNA hybridization confirmed that the six isolates constitute a unique taxon that is distinct from other known species of Vibrio. In addition, this taxon can be readily differentiated phenotypically from other Vibrio species. The six isolates therefore represent a novel species, for which the name Vibrio jasicida sp. nov. is proposed; the novel species is represented by the type strain TCFB 0772 T (5JCM 16453 T 5LMG 25398 T ) (DNA G+C content 45.9 mol%) and reference strains TCFB 1977 (5JCM 16454) and TCFB 1000 (5JCM 16455).Based on multilocus sequence analysis (MLSA), the genus Vibrio comprises 14 distinct clades: Anguillarum, Cholerae, Coralliilyticus, Diazotrophicus, Gazogenes, Fischeri, Halioticoli, Harveyi, Nereis, Nigripulchritudo, Orientalis, Scophthalmi, Splendidus and Vulnificus . Recently, the Fischeri clade was shown to be sufficiently different and members were reclassified in a new genus, Aliivibrio