Rapid differentiation of Prevotella intermedia and P-nigrescens by 16S rDNA PCR-RFLP

Prevotella intermedia and the newly described P. nigrescens cannot be reliably distinguished by phenotypic tests, In this study, restriction endonuclease digestion of amplified 16S rDNA (16S rDNA PCR-RFLP) was used to generate restriction profiles of the type strains of P. intermedia and P. nigrescens and 43 fresh isolates identified as belonging to one of the two species, Whole-cell protein profiles were obtained by SDS-PAGE for comparative purposes, The type strains of P. intermedia and P. nigrescens were easily distinguished by 16S rDNA PCR-RFLP and the fresh isolates were assigned to either species on the basis of their restriction profiles. The identifications obtained were identical to those obtained by protein profiles. 16S rDNA PCR-RFLP is a rapid and reliable method for the differentiation of P. intermedia and P. nigrescens.