Bacteroides faecis sp. nov., isolated from human faeces.

Two anaerobic, Gram-negative, non-motile and non-spore-forming bacterial strains, designated MAJ27(T) and MAJ26, were isolated from human faeces. Both isolates grew optimally at 37 °C, were oxidase- and catalase-negative, were sensitive to bile and produced acid from fermentation of several substrates, including glucose. A study based on 16S rRNA gene sequences showed that both isolates were closely related to type strains of species of the genus Bacteroides. Comparisons of the isolates with Bacteroides thetaiotaomicron VPI 5482(T) and Bacteroides finegoldii JCM 13345(T) showed high levels of 16S rRNA gene sequence similarity (98.6-98.7 and 96.9-97.0 %, respectively), but low levels of DNA-DNA relatedness (≤22 %). The DNA G+C content (42.7±1 mol%) and the major fatty acid (anteiso-C(15 : 0), 39.3-42.5 %) supported the assignment of the isolates to the genus Bacteroides. Based on phenotypic, chemotaxonomic, genotypic and phylogenetic studies, we propose that strains MAJ27(T) and MAJ26 be classified as representing a novel species, Bacteroides faecis sp. nov. The type strain is MAJ27(T) (=KCTC 5823(T)=JCM 16478(T)).