Analysis Of Oral Microbiota In Children With Dental Caries By PCR-DGGE And Barcoded Pyrosequencing

Oral microbiota plays a vital role in maintaining the homeostasis of oral cavity. Dental caries are among the most common diseases in children.Pathogenic bacteria contribute to the development of the disease.However,the overall structure and dynamics of bacterial communities in oral cavity from children with dental caries have not been explored deeply heretofore.In this study,we examined the bacterial diversity of oral microbiota from children with caries in comparison to those from caries-free children using PCR-DGGE and high-throughput barcoded pyrosequencing. Saliva and supragingival plaque samples were collected from 60 children.DNA was isolated from these samples and the hyper-variable V3 region of 16S rDNA genes was amplified using universal primers.A total of 186 787 sequences were obtained and 41 905 unique sequences represented all domains in our study.More than 200 genera belonging to 10 phyla were identified.Our data showed that the oral microbiota in saliva and supragingival plaques could be divided into two clusters and several phylotypes that were significantly different between the two patient groups.The genera of Streptococcus,Veillonella, Actinomyces,Granulicatella,Leptotrichia and Thiomonas in supragingival plaques were associated with dental caries.These genera interacted with each other intimately and changes the composition of the bacterial population destroyed the eubiosis of the microcosm gradually and contributed to the development of dental caries.There was no one specific pathogen but pathogenic communities that correlated with dental caries significantly.And theses pathogenic communities might provide additional targets for dental caries intervention.