title: Bacterial diversity of symptomatic primary endodontic infection by clonal analysis.
abstract: The aim of this study was to explore the bacterial diversity of 10 root canals with acute apical abscess using clonal analysis. Samples were collected from 10 patients and submitted to bacterial DNA isolation, 16S rRNA gene amplification, cloning, and sequencing. A bacterial genomic library was constructed and bacterial diversity was estimated. The mean number of taxa per canal was 15, ranging from 11 to 21. A total of 689 clones were analyzed and 76 phylotypes identified, of which 47 (61.84%) were different species and 29 (38.15%) were taxa reported as yet-uncultivable or as yet-uncharacterized species. Prevotella spp., Fusobacterium nucleatum, Filifactor alocis, and Peptostreptococcus stomatis were the most frequently detected species, followed by Dialister invisus, Phocaeicola abscessus, the uncharacterized Lachnospiraceae oral clone, Porphyromonas spp., and Parvimonas micra. Eight phyla were detected and the most frequently identified taxa belonged to the phylum Firmicutes (43.5%), followed by Bacteroidetes (22.5%) and Proteobacteria (13.2%). No species was detected in all studied samples and some species were identified in only one case. It was concluded that acute primary endodontic infection is characterized by wide bacterial diversity and a high intersubject variability was observed. Anaerobic Gram-negative bacteria belonging to the phylum Firmicutes, followed by Bacteroidetes, were the most frequently detected microorganisms.
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Piracicaba Dental School, Endodontics Division, Piracicaba, SP, Brazil.
authors.forename: Letícia Maria Menezes
authors.initials: LM
authors.lastname: Nóbrega
authors.affiliation: Universidade Federal do Rio Grande do Sul (UFRGS), Department of Conservative Dentistry, Porto Alegre, RS, Brazil.
authors.forename: Francisco
authors.initials: F
authors.lastname: Montagner
authors.affiliation: Universidade de São Paulo (USP), Institute of Biomedical Science, Department of Oral Microbiology, São Paulo, SP, Brazil.
authors.forename: Adriana Costa
authors.initials: AC
authors.lastname: Ribeiro
authors.affiliation: Universidade de São Paulo (USP), Institute of Biomedical Science, Department of Oral Microbiology, São Paulo, SP, Brazil.
authors.forename: Márcia Alves Pinto
authors.initials: MA
authors.lastname: Mayer
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Piracicaba Dental School, Endodontics Division, Piracicaba, SP, Brazil.
authors.forename: Brenda Paula Figueiredo de Almeida
authors.initials: BP
authors.lastname: Gomes
mesh_terms: D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000302:isolation & purification; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003788:Dental Pulp Diseases / Q000382:microbiology*; D016680:Genome, Bacterial; D015698:Genomic Library; D006089:Gram-Negative Anaerobic Bacteria / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D064307:Microbiota; D010482:Periapical Abscess / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S; D017423:Sequence Analysis, RNA
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S