Isolation and identification of Prevotella tannerae from endodontic infections

Black-pigmented bacteria are often isolated from endodontic infections. Fiv e strains of black-pigmented bacteria isolated from endodontic infections c ould not be identified in our laboratory. The purpose of this study was to sequence the 16S rRNA gene of the five unknown isolates and identify the or ganisms. The 16S rRNA genes from the unknown organisms were cloned, sequenc ed, and determined to be Prevotella tannerae. In addition, samples from end odontic infections were surveyed for the presence of the organism. When 118 samples from endodontic infections were examined using polymerase chain re action with specific primers for P. tannerae, 60% of the samples were posit ive for the presence of the organism. This suggests that P. tannerae is com monly present in endodontic infections and could be a potential pathogen.