From a phlegmon in a dog an aerobic and facultatively anaerobic, indole-, oxidase- and catalase-negative, non-motile bacterium was isolated in 2019 in Germany that stained Gram-negative and showed a pleomorphic, rod-shaped, non-spore-forming appearance. Based on the results of 16S rRNA gene sequence analyses, strain IHIT1603-19T was assigned to the genus Streptobacillus with sequence similarities of 98.6, 98.0, 97.9, 97.1 and 94.4 % to the type strains of Streptobacillus felis, Streptobacillus notomytis, Streptobacillus ratti, Streptobacillus moniliformis and Streptobacillus hongkongensis, respectively. Strain IHIT1603-19T could also clearly be differentiated from other Streptobacillus species by rpoB, groEL and recA gene, nucleotide and amino acid sequence analyses as well as by core genome phylogeny. Regarding DNA-DNA relatedness, strain IHIT1603-19T demonstrated an average nucleotide identity of 83.00 and 82.28 % compared to S. felis 131000547T and S. moniliformis DSM 12112T, respectively. Chemotaxonomic and physiological data of strain IHIT1603-19T were in congruence with other closely related members of the family Leptotrichiaceae, represented by highly similar enzyme profiles and fatty acid patterns. MALDI-TOF MS analysis also proved suitable in unequivocally discriminating strain IHIT1603-19T from all currently described taxa of the genus Streptobacillus. On the basis of these data, we propose the novel species Streptobacillus canis sp. nov. with the type strain IHIT1603-19T (=DSM 110501T=CCUG 74118T=CIP 111795T). The G+C content of the DNA of the type strain is 26.6 mol%, genome size is 1.60 Mbp.
Keywords: Canis familiaris; Fusobacteriales; Streptobacillus; canis; dog; novel.