Comprehensive Microbiological Characterization in Children with Localized Aggressive Periodontitis

Objective: We have identified a group of African-American children with localized Aggressive Periodontitis (LAP) within one clinical setting in Florida. The objective of this study was to characterize the subgingival microbiota of this population.

Method: Fifty-six children (34 LAP, 13 healthy siblings, and 9 healthy unrelated controls; mean age 14.4, 13.4 and 13, respectively), were included in this preliminary evaluation. Diagnosis was based upon periodontal probing and radiographic analysis. Subgingival plaque samples taken from diseased (DD) and healthy sites (DH) in LAP children and from healthy sites in siblings (HS) and controls (HC) and were analyzed by the use of 16S rRNA-based microarrays (HOMIM). 

Result: Probes for a total of 422 taxa were hybridized and results were analyzed for prevalence and abundance of the subgingival microflora in the groups. Aggregatibacter actinomycetemcomitans (Aa) was the only species found to be both more prevalent (OR=8.3, CI=2.11-32.9, p=0.0025) and abundant (Aa and P02, p<0.01) in DD, although 6/13 HS harbored this species. Filifactor alocis was also found to be more prevalent in DD sites (OR 2.31, CI 1.06-5.01, p=0.03). Several health-associated species were found to be more prevalent in DH than DD sites, such as species of Selenomonas, Veillonella, and Streptococcus, while some other not typically-detected species, such as Bergeyella sp, Kingella oralis and Neisseria sp were more frequently found in HC and HS, respectively.  Overall, Treponema, Campylobacter, Capnocytophaga, and Cardiobacterium species were found in greater amounts in healthy than in diseased sites.

Conclusion: Based on a comprehensive analysis using HOMIM, Aa is strongly associated with LAP and likely plays a distinct destructive role. In contrast, several health-associated species may play a more protective role against this disease.