[Microbial Community Structure on the Root Surface of Patients with Periodontitis.]

OBJECTIVES: To study the microbial community structure on the root surface of patients with periodontitis. METHODS: Bacterial plaque and tissues from the root neck (RN group),root middle (RM group) and root tine (RT group) of six teeth with mobility 3 in one patient with periodontitis were sampled.The V3V4 region of 16S rRNA was sequenced on the Illumina MiSeq platform.The microbial community structure was analyzed by Mothur,Qiime and SPSS software. RESULTS: The principal component analysis (PCoA) results indicated that the RM samples had a similar microbial community structure as that of the RT samples,which was significant different from that of the RN samples.Thirteen phyla were detected in the three groups of samples,which included 7 dominant phyla.29 dominant genera were detected in 184 genera.The abundance of Bacteroidetes_[G-6] and Peptostre ptococcaceae_[XI][G-4] had a positive correlation with the depth of the collection site of samples (P<0.05),while the abundance of Prevotella,Selenomonas,Corynebacterium and Olsenella had a negative correlation with the depth of the collection site of samples (P<0.05). CONCLUSIONS: There is region-specificity of microbial community structure on the root surface of patients with periodontitis.

[Study on Microbial Diversity of Peri-implantitis Subgingival by High-throughput Sequencing].

OBJECTIVE: To study microbial diversity of peri-implantitis subgingival with high-throughput sequencing, and investigate microbiological etiology of peri-implantitis. METHODS: Subgingival plaques were sampled from the patients with peri-implantitis (D group) and non-peri-implantitis subjects (N group). The microbiological diversity of the subgingival plaques was detected by sequencing V4 region of 16S rRNA with Illumina Miseq platform. The diversity of the community structure was analyzed using Mothur software. RESULTS: A total of 156 507 gene sequences were detected in nine samples and 4 402 operational taxonomic units (OTUs) were found. Selenomonas, Pseudomonas, and Fusobacterium were dominant bacteria in D group, while Fusobacterium, Veillonella and Streptococcus were dominant bacteria in N group. Differences between peri-implantitis and non-peri-implantitis bacterial communities were observed at all phylogenetic levels by LEfSe, which was also found in PcoA test. CONCLUSION: The occurrence of peri-implantitis is not only related to periodontitis pathogenic microbe, but also related with the changes of oral microbial community structure. Treponema, Herbaspirillum, Butyricimonas and Phaeobacte may be closely related to the occurrence and development of peri-implantitis.