The use of a rapid enzymatic test in the field for the detection of anaerobic infections associated with adult periodontitis.

Abstract

The association of certain bacterial species such as Treponema denticola, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Actinobacillus actinomycetemcomitans with destructive periodontitis, allows for the development of diagnostic tests that can detect the presence or overgrowth of one or more species in subgingival plaque samples. A synthetic substrate, n-benzoyl-DL-arginine-$\beta$-naphthylamide (BANA), can detect the presence of trypsin-like enzymes produced by T.denticola, P.gingivalis and B.forsythus, which are not found in over 60 other species present in subgingival plaque samples. The BANA test is a simple, reliable and inexpensive assay that can give information about the presence of at least one of the putative periodontal pathogens in plaque samples, and that can be performed at chairside in 15 minutes. The present study was conducted at the Navy Dental Clinic (OCM) in Rio de Janeiro, Brazil. Clinical and microbiological parameters were obtained from four sites per subject in 301 Brazilian subjects 18-69 years-old. In order to determine the diagnostic value of the BANA test under field conditions, a series of issues were addressed in this investigation: (1) to determine how well the BANA test correlates with the detection of colonization of the root surfaces by T.denticola, P.gingivalis and B.forsythus in Brazilian subjects, as judged by an ELISA system; (2) to determine how well the BANA test and the ELISA system correlate with clinical indices often used in field studies of periodontal diseases (GI, PI, Bleeding and Probing Depth); and (3) to determine whether the frequency and patterns of colonization of the root surfaces within subjects by the putative periodontal pathogens, as detected by the BANA test and by the ELISA system in a segment of the Brazilian population, are similar to the frequency and patterns found in segments of the US population where previous studies utilizing the BANA test have been performed. Results show that: (1) the BANA test provided accurate (90%) information in the field for the detection of T.denticola, P.gingivalis and B.forsythus, as determined by an ELISA system; (2) the BANA test and the ELISA system gave comparable information when tested against clinical parameters and indices of periodontal diseases; (3) a positive BANA test and a positive ELISA test were associated with clinical disease; however, BANA-positive sites and ELISA-positive sites were found where clinical disease was not apparent; (4) a positive BANA test could be best predicted by the presence of T.denticola in the plaque sample; and (5) T.denticola, P.gingivalis and B.forsythus were detected at a high frequency in the periodontal flora of Brazilian subjects, and colonization of periodontal sites by these organisms appeared to be correlated within subjects. Similar findings were found for American subjects.