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

A Gram-negative, facultatively anaerobic bacillus, strain 08MAS2615^T, 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 08MAS2615^T belonged to the genus Proteus, and formed an independent branch which was clearly separated from the other six known species of Proteus. Strain 08MAS2615^T was more closely related to Proteus vulgaris ATCC 29905^T and Proteus penneri NCTC 12737^T than other Proteus species. Similar independent phylogenetic results were obtained using rpoB gene sequence analysis, whereas strain 08MAS2615^T clustered near the species of Proteus cibarius JS9^T and Proteus terrae N5/687^T. Furthermore, the genome-wide core-single nucleotide polymorphism-based phylogenetic tree confirmed that strain 08MAS2615^T 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 08MAS2615^T 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 08MAS2615^T 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 08MAS2615^T represents a novel species of the genus Proteus, for which the name Proteuscolumbae sp. nov. is proposed with strain 08MAS2615^T (=DSM 104686^T=CGMCC 1.15982^T) designated as the species type strain.