A polyphasic taxonomic study was performed on two strains of an unknown Gra
m-positive, catalase-negative, coccus-shaped bacterium isolated from a dead
seal and a harbour porpoise. Comparative 16S rRNA gene sequencing demonstr
ated that the unknown bacterium represents a new subline within the genus V
agococcus close to, but distinct from, Vagococcus fluvialis, Vagococcus lut
rae and Vagococcus salmoninarum. The unknown bacterium was readily distingu
ished from the three currently recognized Vagococcus species by biochemical
tests and electrophoretic analysis of whole-cell proteins. Based on phylog
enetic and phenotypic evidence, it is proposed that the unknown bacterium b
e classified as a new species, Vagococcus fessus. The type strain of Vagoco
ccus fessus is CCUG 41755(T).