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

A bacterial strain, designated 157(T), isolated from human faeces was characterized by using a polyphasic taxonomic approach, which included analysis of physiological and biochemical features, cellular fatty acid profiles, menaquinone profiles and its phylogenetic position, based on 16S rRNA gene sequence analysis. The strain was obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-stain-negative rods. The isolate was able to grown on medium containing 20% (w/v) bile. 16S rRNA gene sequence analysis showed that the strain was a member of the genus Parabacteroides . Strain 157(T) was closely related to Parabacteroides gordonii JCM 15724(T) (96% sequence similarity). The results of hsp60 gene sequence analysis indicated that strain 157(T) was different from P. gordonii JCM 15724(T), with a hsp60 gene sequence similarity of 96.1%. The major cellular fatty acids of strain 157(T) were anteiso-C(15 : 0), iso-C(17 : 0) 3-OH, C(18 : 1)ω9c and anteiso-C(17 : 0) 3-OH. The major menaquinone of the isolate was MK-9. The DNA G+C content of strain 157(T) was 41.8 mol%. On the basis of these data, strain 157(T) represents a novel species of the genus Parabacteroides , for which the name Parabacteroides faecis sp. nov. is proposed; the type strain is 157(T) ( = JCM 18682(T) = CCUG 66681(T)).