title: Microbial analysis in primary and persistent endodontic infections by using pyrosequencing.
abstract: BACKGROUND
  The aim of this study was to investigate the bacterial community profile of intracanal microbiota in primary and persistent endodontic infections associated with asymptomatic chronic apical periodontitis by using GS-FLX Titanium pyrosequencing. The null hypothesis was that there is no difference in diversity of overall bacterial community profiles between primary and persistent infections.
  
  
  METHODS
  Pyrosequencing analysis from 10 untreated and 8 root-filled samples was conducted.
  
  
  RESULTS
  Analysis from 18 samples yielded total of 124,767 16S rRNA gene sequences (with a mean of 6932 reads per sample) that were taxonomically assigned into 803 operational taxonomic units (3% distinction), 148 genera, and 10 phyla including unclassified. Bacteroidetes was the most abundant phylum in both primary and persistent infections. There were no significant differences in bacterial diversity between the 2 infection groups (P > .05). The bacterial community profile that was based on dendrogram showed that bacterial population in both infections was not significantly different in their structure and composition (P > .05).
  
  
  CONCLUSIONS
  The present pyrosequencing study demonstrates that persistent infections have as diverse bacterial community as primary infections.
authors: Division of Periodontology, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut, USA.
authors: Bo-Young
authors: BY
authors: Hong
authors: Tae-Kwon
authors: TK
authors: Lee
authors: Sang-Min
authors: SM
authors: Lim
authors: Seok Woo
authors: SW
authors: Chang
authors: Joonhong
authors: J
authors: Park
authors: Seung Hyun
authors: SH
authors: Han
authors: Qiang
authors: Q
authors: Zhu
authors: Kamran E
authors: KE
authors: Safavi
authors: Ashraf F
authors: AF
authors: Fouad
authors: Kee Yeon
authors: KY
authors: Kum
mesh_terms: D039903:Actinobacteria / Q000145:classification; D000328:Adult; D000368:Aged; D058070:Asymptomatic Diseases; D001419:Bacteria / Q000145:classification*; D041963:Bacteroidetes / Q000145:classification; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003788:Dental Pulp Diseases / Q000382:microbiology*; D045182:Fusobacteria / Q000145:classification; D005673:Fusobacterium / Q000145:classification; D006089:Gram-Negative Anaerobic Bacteria / Q000145:classification; D006090:Gram-Negative Bacteria / Q000145:classification; D006801:Humans; D059013:Microbial Consortia; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000382:microbiology*; D018720:Prevotella / Q000145:classification; D011424:Propionibacterium / Q000145:classification; D020560:Proteobacteria / Q000145:classification; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D017422:Sequence Analysis, DNA; D013144:Spirochaetales / Q000145:classification; D055815:Young Adult
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Diversity; operational taxonomic unit; persistent infection; primary infection; pyrosequencing; richness