MICROBIAL ECOLOGY OF ACTINOBACILLUS-ACTINOMYCETEMCOMITANS, EIKENELLA-CORRODENS AND CAPNOCYTOPHAGA SPP. IN ADULT PERIODONTITIS

Information an intraoral distribution of putative periodontal pathogen s might be essential for controlling different forms of periodontal di sease. Colonization may be either promoted or impeded by other bacteri a competing in the subgingival ecosystem. In recent investigations mic robial associations between dental organisms have been determined in a multitude of subgingival plaque samples within multiple patients and described by odds ratios, In most circumstances without taking into ac count the correlated structure of the observations within a single ind ividual. The present investigation had 3 major objectives: (i) to desc ribe the intraoral distribution of some facultatively anaerobic, Gram- negative rods, i.e. Actinobacillus actinomycetemcomitans, Eikenella co rrodens-like organisms and Capnocytophaga spp., in a multitude of subg ingival and extracrevicular samples of 10 adult subjects with A. actin omycetemcomitans-associated periodontitis; (ii) to analyse possible in consistencies of microbial associations between these periodontal orga nisms; and (iii) to determine factors increasing the likelihood of iso lating these bacteria in a given subgingival site by employing General ized Estimation Equation (GEE) methods. Clinical examinations were car ried out at 6 sites of every tooth present. In each subject. 13 extrac revicular (2 cheek mucosa, 3 tongue, 4 gingival, 2 tonsillar samples, 1 palatinal, 1 saliva sample) and between 22 and 44 subgingival sample s from deepest sites of every tooth present (n=296) were selectively c ultivated for A. actinomycetemcomitans, E. corrodens and Capnocytophag a spp. In extracrevicular material, A. actinomycetemcomitans, Capnocyt ophaga spp. and E. corrodens were isolated in 9, 10 and 6 patients, an d from 65, 82 and 15% samples, respectively. The organisms were recove red from 51, 62 and 27% subgingival plaque samples, respectively. Hete rogeneity tests did not reveal significant inconsistencies of microbia l associations between bacteria in subgingival plaque. Mantel-Haenszel 's odds ratios ranged between 2.0 for A. actinomycetemcomitans and Cap nocytophaga spp. and 18.7 for Capnocytophaga spp. and E. corrodens. An exchangeable working dependence structure was employed in the GEE app roach. The odds of isolating A. actinomycetemcomitans was increased by factor 3.7 in 4-6 mm deep pockets, and 9.5 in greater than or equal t o 7 mm deep pockets. The odds of presence of E. corrodens was increase d by factor 10.8 in the case of presence of Capnocytophaga spp. and 2. 1 in the case of presence of A. actinomycetemcomitans. Capnocytophaga spp. were associated with bleeding on probing and molar sites. Presenc e of E. corrodens was associated with clinical attachment loss but not periodontal probing depth. Results of the present study indicated an association of A. actinomycetemcomitans with periodontal pathology. Wh ereas this organism and Cagnocytophagae were widely distributed in ext racrevicular ecosystems of the mouth, E. corrodens only occasionally a ppeared in saliva or on mucous membranes of the oral cavity. In genera l, GEE methods seem to allow to determine factors associated with the presence of periodontal organisms in a multivariate approach and consi dering the correlated structure of the data.