Microbial diversity in failed endodontic root-filled teeth  

作　　者：ZHANG Chen HOU Ben-xiang ZHAO Huan-ying SUN Zheng 

机构地区：[1]School of Stomatology, Capital Medical 100050, China [2]Medical Experiment and Test Center, Capital Medical University, Beijing 100069, China

出　　处：《Chinese Medical Journal》2012年第6期1163-1168,共6页中华医学杂志（英文版）

基　　金：This study was supported by grants from the National Natural Science Foundation of China （No. 30872877 and No. 81170952）.

摘　　要：Background Persistent/secondary infections of human root canals play an important role in the failure of endodontic treatment. This study used 16S rRNA sequencing to assess microbial diversity in root-filled teeth associated with failed endodontic treatment. Methods DNA was extracted from 15 teeth with persistent intraradicular infections, and the 16S rRNA of all present bacteria were amplified by PCR, followed by cloning and sequencing of the 16S rRNA amplicons. Results All sample extracts were positive for PCR amplification using the universal 16S rRNA gene primers. Negative control reactions yielded no amplicons. Sixty-five phylotypes belonging to seven phyla were identified from 760 clones; a mean of 9.4 phylotypes were detected in each sample （range 3-15）. Twenty-eight phylotypes were detected in more than one sample, revealing a high inter-sample variability. Parvimonas micra （60%, 9/15）, Solobacterium moore （47%, 7/15）, Dialister invisus （33%, 5/15）, Enterococcus faecalis （33%, 5/15）, Filifactor alocis （27%, 4/15）, and Fusobacterium nucleatum （27%, 4/15） were the prevalent species. Nineteen as-yet-uncultivated phylotypes were identified, comprising a substantial proportion of the bacteria in many cases. Conclusions Persistent intraradicular infections were present in all root-filled teeth associated with failed endodontic treatment. The current observations reveal new candidate endodontic pathogens, including as-yet-uncultivated bacteria and phylotypes that may participate in the mixed infections associated with post-treatment apical periodontitis.Background Persistent/secondary infections of human root canals play an important role in the failure of endodontic treatment. This study used 16S rRNA sequencing to assess microbial diversity in root-filled teeth associated with failed endodontic treatment. Methods DNA was extracted from 15 teeth with persistent intraradicular infections, and the 16S rRNA of all present bacteria were amplified by PCR, followed by cloning and sequencing of the 16S rRNA amplicons. Results All sample extracts were positive for PCR amplification using the universal 16S rRNA gene primers. Negative control reactions yielded no amplicons. Sixty-five phylotypes belonging to seven phyla were identified from 760 clones; a mean of 9.4 phylotypes were detected in each sample （range 3-15）. Twenty-eight phylotypes were detected in more than one sample, revealing a high inter-sample variability. Parvimonas micra （60%, 9/15）, Solobacterium moore （47%, 7/15）, Dialister invisus （33%, 5/15）, Enterococcus faecalis （33%, 5/15）, Filifactor alocis （27%, 4/15）, and Fusobacterium nucleatum （27%, 4/15） were the prevalent species. Nineteen as-yet-uncultivated phylotypes were identified, comprising a substantial proportion of the bacteria in many cases. Conclusions Persistent intraradicular infections were present in all root-filled teeth associated with failed endodontic treatment. The current observations reveal new candidate endodontic pathogens, including as-yet-uncultivated bacteria and phylotypes that may participate in the mixed infections associated with post-treatment apical periodontitis.

关 键 词：BACTERIA infection endodontic treatment RNA sequencing 

分 类 号：Q938.1[生物学—微生物学] TH787.1[机械工程—仪器科学与技术]