Prevotella shahii sp. nov. and Prevotella salivae sp. nov., isolated from the human oral cavity.

Two bacterial strains, EHS11(T) and EPSA11(T), which were isolated from the human oral cavity, were characterized in terms of phenotypic and biochemical characteristics, cellular fatty acid profiles and phylogenetic position based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that each of the isolates belonged to a novel species of the genus Prevotella. Strain EHS11(T) was related to Prevotella loescheii (about 95 % similarity), whereas strain EPSA11(T) was related to Prevotella oris (about 94 % similarity). Both strains were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-negative rods. The cellular fatty acid composition of strain EPSA11(T) was very similar to that of P. oris JCM 8540(T). On the other hand, the cellular fatty acid composition of strain EHS11(T) was significantly different from those of other Prevotella species. The predominant fatty acids in strain EHS11(T) are C(18 : 1)omega9c, C(16 : 0) and C(16 : 0) 3-OH, whereas other Prevotella species, except for P. loescheii JCM 8530(T), possess anteiso-C(15 : 0), iso-C(17 : 0) 3-OH and C(18 : 1)omega9c. The predominant fatty acids in P. loescheii JCM 8530(T) are anteiso-C(15 : 0), C(16 : 0) and C(18 : 1)omega9c. DNA-DNA hybridization experiments revealed a genomic distinction of strains EHS11(T) and EPSA11(T) from P. loescheii JCM 8530(T) and P. oris JCM 8540(T). On the basis of these data, two novel Prevotella species are proposed: Prevotella shahii sp. nov. and Prevotella salivae sp. nov. The type strains of P. shahii and P. salivae are EHS11(T) (=JCM 12083(T)=DSM 15611(T)) and EPSA11(T) (=JCM 12084(T)=DSM 15606(T)), respectively.