Prevotella multisaccharivorax sp. nov., isolated from human subgingival plaque

Six bacterial strains isolated from the human oral cavity, PPPA16, PPPA20(T), PPPA24, PPPA31, EPPA6 and EPPA7, were characterized by determining phenotypic and biochemical features, cellular fatty acid profiles, menaquinone profiles and phylogenetic position based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that the isolates represented the same species of the genus Prevotella. The strains were related to Prevotella dentalis with about 89% similarity. In addition, the isolates were related to Prevotella sp. oral clone IDR-CEC-0032, which is a representative of the numerically dominant cluster VI in carious dentine lesions [Nadkarni et al. (2004). J Clin Microbiol 42, 5238-5244], with about 99% similarity. The strains were obligately anaerobic, non-pigmenting, non-spore-forming, non-motile, Gram-negative rods. The isolates could be differentiated from other Prevotella species by D-mannitol, D-melezitose, D-sorbitol and D-trehalose fermentation in API 20A tests. The cellular fatty acid composition of strains PPPA16, PPPA20(T), PPPA24, PPPA31, EPPA6 and EPPA7 was significantly different from that of other Prevotella species. Compared with other Prevotella species, only these six strains contained dimethyl acetals. The major menaquinones of the clinical isolates were MK-12 and MK-13, whereas the major menaquinones of other Prevotella species were MK-10 and MK-11. On the basis of these data, a novel Prevotella species, Prevotella multisaccharivorax sp. nov., is proposed, with PPPA20(T) (=JCM 12954(T)=DSM 17128(T)) as the type strain.