Abstract
Three strains of anaerobic, non-pigmented, Gram-negative bacilli isolated from various human clinical samples were characterized in terms of phenotypic and genotypic tests, including sequence analysis of 16S rRNA and rpoB genes. The strains were most closely related to the type strains of Prevotella marshii and Prevotella shahii on the basis of both 16S rRNA (89.8 and 89.0 % identity, respectively) and rpoB gene sequences (83.1 and 82.8 % identity, respectively). Phylogenetic analysis showed that the isolates constituted a robust homogeneous group distinct from known species in the genus Prevotella . The rrn skeleton (as determined by PFGE) and the DNA G+C content, determined to be 39.4 mol% for strain LBN 293 T , distinguished the novel isolates from the type strains of P. marshii and P. shahii . The three strains were saccharolytic and produced acetic, lactic and succinic acids as major metabolic end products. Polyphasic investigations supported the proposal of a novel species, Prevotella nanceiensis sp. nov., with LBN 293 T (=AIP 261.03 T =CIP 108993 T =CCUG 54409 T ) as the type strain.