16S rRNA sequence determination for members of the genus Carnobacterium and related lactic acid bacteria and description of Vagococcus salmoninarum sp. nov.

The phylogenetic interrelationships of members of the genus Carnobacterium and some atypical lactobacilli isolated from diseased salmonid fish were investigated by using reverse transcriptase sequencing of 16S rRNA. The four species Carnobacterium piscicola, Carnobacterium divergens, Carnobacterium gallinarum, and Carnobacterium mobile exhibited a high degree of sequence similarity with each other (ca. 96 to 98%) and formed a phylogenetically coherent group that was quite distinct from all other lactic acid bacteria. The sequence data clearly demonstrated that carnobacteria are phylogenetically closer to the genera Enterococcus and Vagococcus than to members of the genus Lactobacillus. The strains from fish were found to be phylogenetically related to the genus Vagococcus and represent a new species, Vagococcus salmoninarum. The type strain of Vagococcus salmoninarum is strain NCFB 2777.