DETECTION OF PUTATIVE PERIODONTAL PATHOGENS IN SUBGINGIVAL SPECIMENS BY 16S RIBOSOMAL DNA AMPLIFICATION WITH THE POLYMERASE CHAIN-REACTION

The utility of the 16S ribosomal RNA-based polymerase chain reaction ( PCR) for detection of Actinobacillus actinomycetemcomitans, Bacteroide s forsythus, Campylobacter rectus, Eikenella corrodens, Porphyromanas gingivalis, Prevotella intermedia, and Treponema denticola was examine d and compared with that of anaerobic culture. Primer pairs consisting of 20-27 nucleotides amplified 404- to 688-bp regions of 16S ribosoma l RNA genes of these organisms. This method had a lower detection limi t of 50 target cells in a background of 10(7) cells. Its specificity f or B. forsythus, P. gingivalis, and T. denticola seemed high. The prim ers for A. actinomycetemcomitans, C. rectus, and P. intermedia cross-r eacted with some closely related species but did not reveal amplificat ion products in tests with more distantly related organisms. The prime rs for E. corrodens did not seem to cross-react with oral organisms. T his PCR technique was sensitive, reproducible, and easy to perform. PC R-based amplification may prove valuable for the detection of some per iodontal pathogens in crude subgingival specimens.