Saturday, March 24, 2012: 9:45 a.m. - 11 a.m.
Presentation Type: Poster Session
Introduction: Caries and periodontitis, two bacterially induced diseases, have a strong ethnic predilection. Therefore, examining the influence of ethnicity on bacterial colonization of health-compatible oral biofilms is important to elucidate its contribution to disease susceptibility. Objective: To compare the microbial profiles of dentally and periodontally healthy subjects belonging to four ethnicities using open-ended molecular assays to identify microbial community profiles. Methods: Supragingival and subgingival plaque samples were collected from 192 adults of Caucasian, African-American, Hispanic, and Chinese ethnicities. All subjects reported no systemic disease, pregnancy, and recent or prophylactic antibiotic use. Bacterial DNA was analyzed using terminal restriction fragment length polymorphism (t-RFLP) and 454 pyrosequencing targeting the 16S rRNA gene. Chimera-depleted sequences were compared against a curated database. Bacterial levels and t-RFLP peak sizes were transformed and compared between ethnic groups using parametric tests (p<0.05). UniFrac was used for community profile comparisons. Random Forest Machine learning Classifier was used to determine the efficacy of oral microbial signatures as a predictor of ethnicity. Results: All ethnicities demonstrated unique microbial profiles, even though a core microbiome consisting of eight species and phylotypes was present in all individuals. Both supragingival and subgingival communities demonstrated significant clustering of t-RFLP patterns based on ethnicity. Sequence analysis revealed significant differences in community diversity and species profiles between ethnicities. Four species of the core microbiome demonstrated significantly different abundances between groups. Also, 75% of the bacterial community within each ethnic group was derived from different bacterial lineages. The microbial signature was capable of predicting ethnicity in all groups with at least 54% accuracy, and at least 80% accuracy when discriminating African Americans from Chinese and HIspanics. Conclusions: There is a significant association between ethnic preference and the bacterial composition of the health- compatible oral microbiome. Microbial signatures are capable of discriminating between ethnicities.This abstract is based on research that was funded entirely or partially by an outside source: Ohio State College of Dentistry CTOC T32 DE 0143220 training grant, NIH R03DE018734-02
Keywords: Biofilm, Ethnicity, Microbiology, Molecular biology and Periodontal organisms