SIMILARITY OF SALIVARY AND SUBGINGIVAL PREVOTELLA-INTERMEDIA AND PREVOTELLA-NIGRESCENS ISOLATES BY ARBITRARILY PRIMED POLYMERASE CHAIN-REACTION

The distribution and the genetic similarity of Prevotella intermedia a nd Prevotella nigrescens in saliva and in subgingival samples recovere d from the same subject were studied in 16 subjects with different per iodontal status. The isolates (4 salivary and 4 subgingival P. interme dia/nigrescens group isolates per subject) were identified to species level by hybridization with species-specific oligonucleotide probes, a nd the clonal analysis was performed using arbitrarily primed polymera se chain reaction (AP-PCR) (all isolates) and ribotyping (isolates fro m 5 subjects). In addition, the applicability of AP-PCR in differentia ting between P. intermedia and P. nigrescens species was tested using 18 P. intermedia and 20 P. nigrescens isolates from 34 subjects. P. in termedia was detected in 7 and P. nigrescens in 14 of the 16 subjects. In all subjects the same species was found both in saliva and in subg ingival plaque. In 15 of the 16 subjects, similar AP-PCR types of P. i ntermedia and/or P. nigrescens between salivary and subgingival sample s were found. The salivary and subgingival isolates that were similar by AP-PCR were indistinguishable also by ribotyping. The AP-PCR analys is revealed a P. intermedia or P. nigrescens species-specific AP-PCR p roduct in most isolates. This study indicates that both P. intermedia and P. nigrescens were found both in salivary and in subgingival sampl es, and both sampling sites within the same individual were usually co lonized with identical AP-PCR types of the species. Thus, in addition to a subgingival sample a salivary sample seems to be suitable for det ection and clonal analysis of these species. The AP-PCR method proved to be a simple method applicable for differentiation and clonal analys is of P. intermedia and P. nigrescens.