title: Comparison of the bacterial composition and structure in symptomatic and asymptomatic endodontic infections associated with root-filled teeth using pyrosequencing.
abstract: Residual microorganisms and/or re-infections are a major cause for root canal therapy failure. Understanding of the bacterial content could improve treatment protocols. Fifty samples from 25 symptomatic and 25 asymptomatic previously root-filled teeth were collected from Sudanese patients with periradicular lesions. Amplified 16S rRNA gene (V1-V2) variable regions were subjected to pyrosequencing (FLX 454) to determine the bacterial profile. Obtained quality-controlled sequences from forty samples were classified into 741 operational taxonomic units (OTUs) at 3% dissimilarity, 525 at 5% dissimilarity and 297 at 10% dissimilarity, approximately corresponding to species-, genus- and class levels. The most abundant phyla were: Firmicutes (29.9%), Proteobacteria (26.1%), Actinobacteria (22.72%), Bacteroidetes (13.31%) and Fusobacteria (4.55%). Symptomatic patients had more Firmicutes and Fusobacteria than asymptomatic patients, while asymptomatic patients showed more Proteobacteria and Actinobacteria. Interaction of disease status and age was observed by two-way ANOSIM. Canonical correspondence analysis for age, tooth restoration and disease status showed a correlation of disease status with the composition and prevalence of different members of the microbial community. The pyrosequencing analysis revealed a distinctly higher diversity of the microbiota compared to earlier reports. The comparison of symptomatic and asymptomatic patients showed a clear association of the composition of the bacterial community with the presence and absence of symptoms in conjunction with the patients' age.
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Annette Carola
authors.initials: AC
authors.lastname: Anderson
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Ahmad
authors.affiliation: Khartoum Center for Research and Medical Training, Khartoum, Sudan.
authors.forename: Fadil
authors.initials: F
authors.lastname: Elamin
authors.affiliation: Institute of Environmental Medicine and Hospital Hygiene, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Jonas
authors.affiliation: Khartoum Center for Research and Medical Training, Khartoum, Sudan.
authors.forename: Yousra
authors.initials: Y
authors.lastname: Mirghani
authors.affiliation: Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schilhabel
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Lamprini
authors.initials: L
authors.lastname: Karygianni
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Hellwig
authors.affiliation: Institute of Environmental Medicine and Hospital Hygiene, Albert-Ludwigs-University, Freiburg, Germany.
authors.forename: Ateequr
authors.initials: A
authors.lastname: Rehman
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001424:Bacterial Infections / Q000235:genetics / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics*; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D011671:Pulpitis / Q000235:genetics / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial