title: Peri-implant and periodontal microbiome diversity in aggressive periodontitis patients: a pilot study.
abstract: OBJECTIVE
  To investigate the bacterial microbiome in periodontal and peri-implant biofilms deriving from aggressive periodontitis patients (AgP) in conditions of health and disease.
  
  
  METHODS
  Ninety-one plaque samples were collected from 18 patients previously diagnosed and treated for AgP. The samples were taken from (i) 24 residual periodontal pockets (TD) (n = 6 patients), (ii) 24 healthy periodontal sites (TH) (n = 6 patients), (iii) 24 dental sites from the same implant patients (TM) (n = 6 patients), (iv) 5 peri-implantitis sites (II) (n = 2 patients), (v) 6 peri-mucositis sites (IM) (n = 2 patients) and (vi) 8 healthy implant sites (IH) (n = 2 patients). All subjects underwent periodontal clinical and radiographic assessments. Bacterial DNA was extracted, PCR amplified using 16S rRNA gene V5-V7 primers (barcoded amplicons 785F;1175R), purified, pooled at equimolar concentrations and sequenced (MiSeq, Illumina) yielding 250 bp paired-end reads. The 16S rRNA reads were filtered, assembled and analysed.
  
  
  RESULTS
  The genera Propionibacterium, Paludibacter, Staphylococcus, Filifactor, Mogibacterium, Bradyrhizobium and Acinetobacter were unique to peri-implant sites (P = 0.05). In TM samples, different proportions and bacterial spp. were found when compared with the same patients' samples at implant sites. Specifically, Actinomyces (P = 0.013) and Corynebacterium (P = 0.030) genera showed to be significantly more abundant in the TM group when compared to the II. The highest phylogenetic diversity was observed in residual periodontal pocket sites (TD). Increased annual tooth loss rate and residual pocketing was related to high proportions of the genera Actinomyces, Porphyromonas, Prevotella, Streptococcus, Actinomycetaceae, TM7-3, Selenomonas, and Dialister, Treponema, Parvimonas and Peptostreptococcus in the TD group.
  
  
  CONCLUSIONS
  Within the limitations of this pilot study, the periodontal and peri-implant microbiome presents a dissimilar taxonomic composition across different niches within AgP patients. The host response, the habitat structure and the vast coexistence of strains and species surrounding implants and teeth in health and disease are likely to be shaping the heterogeneous composition of the subgingival biofilms. The TM7 phylum was found only in TD cases. The investigation of the impact of periodontal and peri-implant keystone species on these complex ecosystems in states of health and disease seems to be essential.
authors.affiliation: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.|Centre for Oral Clinical Research, Institute of Dentistry, Barts & The London School of Medicine & Dentistry, QMUL, London, UK.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Sousa
authors.affiliation: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.|Centre for Oral Clinical Research, Institute of Dentistry, Barts & The London School of Medicine & Dentistry, QMUL, London, UK.
authors.forename: Luigi
authors.initials: L
authors.lastname: Nibali
authors.affiliation: Department of Microbial Diseases, UCL Eastman Dental Institute, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Spratt
authors.affiliation: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.
authors.forename: Jose
authors.initials: J
authors.lastname: Dopico
authors.affiliation: Centre for Adult Oral Health, Institute of Dentistry, Barts & The London School of Medicine & Dentistry, QMUL, London, UK.
authors.forename: Nikos
authors.initials: N
authors.lastname: Mardas
authors.affiliation: Biostatistics Unit, UCL Eastman Dental Institute, London, UK.
authors.forename: Aviva
authors.initials: A
authors.lastname: Petrie
authors.affiliation: Periodontology Unit, Department of Clinical Research, UCL Eastman Dental Institute, London, UK.|Centre for Oral Clinical Research, Institute of Dentistry, Barts & The London School of Medicine & Dentistry, QMUL, London, UK.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Donos
mesh_terms: D000328:Adult; D010520:Aggressive Periodontitis / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development; D004269:DNA, Bacterial / Q000235:genetics; D015921:Dental Implants / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota; D008875:Middle Aged; D057873:Peri-Implantitis / Q000382:microbiology; D010514:Periodontal Pocket / Q000382:microbiology; D010519:Periodontium / Q000378:metabolism*; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D015921:Dental Implants; D012336:RNA, Ribosomal, 16S