Peptostreptococcus stomatis sp. nov., isolated from the human oral cavity.

Seven strains of anaerobic Gram-positive cocci isolated from human oral sites were subjected to a comprehensive range of phenotypic and genotypic tests. 16S rRNA gene sequence analysis revealed that the strains constituted a homogeneous group that was distinct from species with validly published names, but related to Peptostreptococcus anaerobius. All oral strains tested belonged to this group, whereas all non-oral strains studied were confirmed as P. anaerobius. A novel species, Peptostreptococcus stomatis sp. nov., is proposed to accommodate these oral strains. P. stomatis is weakly saccharolytic and produces acetic, butyric, isobutyric, isovaleric and isocaproic acids as end products of fermentation. The type strain of P. stomatis is W2278T (=DSM 17678T = CCUG 51858T); the G+C content of the DNA of this strain is 36 mol%.