title: Microbiome of Deep Dentinal Caries Lesions in Teeth with Symptomatic Irreversible Pulpitis.
abstract: This study used a next-generation sequencing approach to identify the bacterial taxa occurring in the advanced front of caries biofilms associated with pulp exposure and irreversible pulpitis. Samples were taken from the deepest layer of dentinal caries lesions associated with pulp exposure in 10 teeth diagnosed with symptomatic irreversible pulpitis. DNA was extracted and the microbiome was characterized on the basis of the V4 hypervariable region of the 16S rRNA gene by using paired-end sequencing on Illumina MiSeq device. Bacterial taxa were mapped to 14 phyla and 101 genera composed by 706 different OTUs. Three phyla accounted for approximately 98% of the sequences: Firmicutes, Actinobacteria and Proteobacteria. These phyla were also the ones with most representatives at the species level. Firmicutes was the most abundant phylum in 9/10 samples. As for genera, Lactobacillus accounted for 42.3% of the sequences, followed by Olsenella (13.7%), Pseudoramibacter (10.7%) and Streptococcus (5.5%). Half of the samples were heavily dominated by Lactobacillus, while in the other half lactobacilli were in very low abundance and the most dominant genera were Pseudoramibacter, Olsenella, Streptococcus, and Stenotrophomonas. High bacterial diversity occurred in deep dentinal caries lesions associated with symptomatic irreversible pulpitis. The microbiome could be classified according to the relative abundance of Lactobacillus. Except for Lactobacillus species, most of the highly prevalent and abundant bacterial taxa identified in this study have been commonly detected in infected root canals. The detected taxa can be regarded as candidate pathogens for irreversible pulpitis and possibly the pioneers in pulp invasion to initiate endodontic infection.
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
authors.forename: Isabela N
authors.initials: IN
authors.lastname: Rôças
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
authors.forename: Flávio R F
authors.identifier: 0000-0002-9922-8202
authors.initials: FR
authors.lastname: Alves
authors.affiliation: Institute of Microbiology Prof. Paulo de Góes, Federal University of Rio de Janeiro, RJ, Brazil.
authors.forename: Caio T C C
authors.initials: CT
authors.lastname: Rachid
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Kenio C
authors.initials: KC
authors.lastname: Lima
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Isauremi V
authors.initials: IV
authors.lastname: Assunção
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Patrícia N
authors.initials: PN
authors.lastname: Gomes
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000235:genetics; D000293:Adolescent; D000328:Adult; D003731:Dental Caries / Q000382:microbiology*; D005260:Female; D000068536:Bacillota / Q000145:classification / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007778:Lactobacillus / Q000145:classification / Q000235:genetics; D008297:Male; D064307:Microbiota / Q000235:genetics*; D008875:Middle Aged; D020560:Proteobacteria / Q000145:classification / Q000235:genetics; D011671:Pulpitis / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020588:Stenotrophomonas / Q000145:classification / Q000235:genetics; D013291:Streptococcus / Q000145:classification / Q000235:genetics; D055815:Young Adult
chemical_list: D012336:RNA, Ribosomal, 16S