Relationship of periodontopathic bacteria with early-onset periodontitis in Down's syndrome

Background: Down's syndrome (DS) patients often develop severe early-onset marginal periodontitis in early adulthood; however, there is little informa tion available on the microbiology of DS periodontitis. Methods: Subgingival plaque specimens were taken from 67 DS young adults an d 41 age-matched systemically healthy individuals with mental disabilities (MD). The prevalence of 10 possible periodontopathic bacterial species, Act inobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides fo rsythus, Treponema denticola, Prevotella intermedia, Prevotella nigrescens, Capnocytophaga ochracea, Capnocytophaga sputigena, Campylobacter rectus, a nd Eikonella corrodens, were investigated in their subgingival plaque sampl es using a polymerase chain reaction method. The detection of P. gingivalis fimA genotypes was also performed in P. gingivalis-positive samples. Results: Although DS subjects generally develop an earlier and more extensi ve periodontal breakdown than those with MD, no significant differences wer e observed in the bacterial profiles. The profiles of subjects with periodo ntitis were significant in DS, but not in MD. The prevalence of P. gingival is, B. forsythus, and P. intermedia were significant in the DS periodontiti s group, compared to DS gingivitis group. Moreover, the occurrence of P. gi ngivalis with the type II fimA gene was significantly related to periodonti tis in both DS and MD, with odds ratios of 6.32 and 12.03, respectively. Conclusions: These results suggest that early-onset periodontitis in DS is mainly due to the more susceptible host for the causative microbial agents including P. gingivalis with type II fimA.