Proteus columbae sp. nov., isolated from a pigeon in Ma'anshan, China.

A Gram-negative, facultatively anaerobic bacillus, strain 08MAS2615T, was isolated from the flesh of a pigeon specimen collected in Ma'anshan, Anhui province, China. Phylogenetic analysis of 16S rRNA gene sequences confirmed that strain 08MAS2615T belonged to the genus Proteus, and formed an independent branch which was clearly separated from the other six known species of Proteus. Strain 08MAS2615T was more closely related to Proteus vulgaris ATCC 29905T and Proteus penneri NCTC 12737T than other Proteus species. Similar independent phylogenetic results were obtained using rpoB gene sequence analysis, whereas strain 08MAS2615T clustered near the species of Proteus cibarius JS9T and Proteus terrae N5/687T. Furthermore, the genome-wide core-single nucleotide polymorphism-based phylogenetic tree confirmed that strain 08MAS2615T formed a monophyletic and robust clade. Based on whole-genome sequences, the range of in silico DNA-DNA hybridization and average nucleotide identity between strain 08MAS2615T and the six Proteus species were 25.5-48.8 % and 82.8-92.9 %, respectively, less than the proposed cutoff level for species delineation, i.e. 70 and 95 %. In addition, the major cellular fatty acid profile of strain 08MAS2615T was C14 : 0 (12.4 %), C16 : 0 (23.8 %), C17 : 0cyclo (14.4 %), summed feature 2 (C16 : 1iso I/C14 : 0 3-OH) (11.0 %), summed feature 3 (C16 : 1ω7c/16 : 1ω6c) (18.5 %) and summed feature 8 (C18 : 1ω6c) (18.6 %). On the basis of these results, strain 08MAS2615T represents a novel species of the genus Proteus, for which the name Proteuscolumbae sp. nov. is proposed with strain 08MAS2615T (=DSM 104686T=CGMCC 1.15982T) designated as the species type strain.