Arcanobacterium canis sp. nov., isolated from otitis externa of a dog, and emended description of the genus Arcanobacterium Collins et al. 1983 emend. Yassin et al. 2011

Abstract

A polyphasic taxonomic study was performed on an unidentified Arcanobacterium -like Gram-stain-positive bacterium isolated from otitis externa of a dog. Comparative 16S rRNA gene sequencing showed that the bacterium belonged to the genus Arcanobacterium and was most closely related to the type strains of Arcanobacterium haemolyticum (97.2 %), Arcanobacterium hippocoleae (96.5 %) and Arcanobacterium phocae (96.4 %). The presence of the major menaquinone MK-9(H4) supported the affiliation of this strain to the genus Arcanobacterium . The polar lipid profile contained the major lipids phosphatidylcholine, diphosphatidylglycerol, phosphatidylinositol mannoside and an unidentified phospholipid (PL2). Major fatty acids were C14 : 0, C16 : 0, C18 : 0, C18 : 1ω9c and C18 : 2ω6,9c/anteiso-C18 : 0 (detected as a summed feature). C10 : 0 and C12 : 0 were present in minor amounts. The results of physiological and biochemical testing clearly distinguished the unknown bacterium from other species of the genus Arcanobacterium . Based on these tests, it is proposed that the unknown bacterium should be classified in the novel species Arcanobacterium canis sp. nov. The type strain of Arcanobacterium canis is P6775T ( = CCM 7958T  = CCUG 61573T  = CIP 110339T). An emended description of the genus Arcanobacterium is also provided.