Parabacteroides faecis sp. nov., isolated from human faeces

Abstract

A bacterial strain, designated 157T, 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 157T was closely related to Parabacteroides gordonii JCM 15724T (96 % sequence similarity). The results of hsp60 gene sequence analysis indicated that strain 157T was different from P. gordonii JCM 15724T, with a hsp60 gene sequence similarity of 96.1 %. The major cellular fatty acids of strain 157T were anteiso-C15 : 0, iso-C17 : 0 3-OH, C18 : 1ω9c and anteiso-C17 : 0 3-OH. The major menaquinone of the isolate was MK-9. The DNA G+C content of strain 157T was 41.8 mol%. On the basis of these data, strain 157T represents a novel species of the genus Parabacteroides , for which the name Parabacteroides faecis sp. nov. is proposed; the type strain is 157T ( = JCM 18682T = CCUG 66681T).