Restriction fragment-length polymorphism analysis of 16S rDNA from oral asaccharolytic Eubacterium species amplified by polymerase chain reaction

Restriction fragment-length polymorphism (RFLP) analysis of 16S rDNA amplified by polymerase chain reaction was used to generate restriction profiles of the type strains of oral asaccharolytic Eubacterium species, that is, Eubacterium brachy, Eubacterium exiguum, Eubacterium lentum, Eubacterium minutum, Eubacterium nodatum, Eubacterium saphenum, Eubacterium timidum and 33 asaccharolytic Eubacterium strains isolated from oral sites. The 16S rRNA gene sequences from isolated genomic DNA samples were amplified by polymerase chain reaction (PCR). PCR products were purified and characterized by single digestions with 7 restriction endonucleases. Among the 7 endonucleases, HpaII was found to discriminate the respective reference strains. Twenty-three isolates, out of 33, were assigned to one of the reference species, on the basis of their restriction profiles by digestion with HpaII. The remaining 10 isolates could not be assigned to any of the established species and constituted 4 distinct groups, each of which may be a new species.