Parabacteroides gordonii sp. nov., isolated from human blood cultures.

Three bacterial strains that had been isolated from human blood cultures, MS-1(T), MS-2 and MS-3, were characterized for their phenotypic and biochemical features, cellular fatty acid profiles, menaquinone profiles and phylogenetic positions based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that the isolates were members of the genus Parabacteroides. These isolates were most closely related to Parabacteroides goldsteinii JCM 13446(T), with 95.9 % 16S rRNA gene sequence similarity. The levels of sequence similarity among the three strains were 99.7-100 %. The isolates were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-negative and rod-shaped. The strains grew on media containing 20 % bile. These strains could be differentiated from P. goldsteinii by their ability to ferment l-arabinose and inabilities to ferment cellobiose, l-rhamnose and trehalose or to hydrolyse aesculin. The major menaquinone of the isolates was MK-10. Based on these data, we propose a novel Parabacteroides species, Parabacteroides gordonii sp. nov. The type strain is MS-1(T) (=JCM 15724(T) =CCUG 57478(T)).