title: Microbiological and immunological characteristics of young Moroccan patients with aggressive periodontitis with and without detectable Aggregatibacter actinomycetemcomitans JP2 infection.
abstract: Cross-sectional and longitudinal studies identify the JP2 clone of Aggregatibacter actinomycetemcomitans as an aetiological agent of aggressive periodontitis (AgP) in adolescents of northwest African descent. To gain information on why a significant part of Moroccan adolescents show clinical signs of periodontal disease in the absence of this pathogen we performed comprehensive mapping of the subgingival microbiota of eight young Moroccans, four of whom were diagnosed with clinical signs of AgP. The analysis was carried out by sequencing and phylogenetic analysis of a total of 2717 cloned polymerase chain reaction amplicons of the phylogenetically informative 16S ribosomal RNA gene. The analyses revealed a total of 173 bacterial taxa of which 39% were previously undetected. The JP2 clone constituted a minor proportion of the complex subgingival microbiota in patients with active disease. Rather than identifying alternative aetiologies to AgP, the recorded infection history of the subjects combined with remarkably high concentrations of antibodies against the A. actinomycetemcomitans leukotoxin suggest that disease activity was terminated in some patients with AgP as a result of elimination of the JP2 clone. This study provides information on the microbial context of the JP2 clone activity in a JP2-susceptible population and suggests that such individuals may develop immunity to AgP.
authors.affiliation: Department of Medical Microbiology and Immunology, Aarhus University, Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Rylev
authors.forename: M
authors.initials: M
authors.lastname: Bek-Thomsen
authors.forename: J
authors.initials: J
authors.lastname: Reinholdt
authors.forename: O-K
authors.initials: OK
authors.lastname: Ennibi
authors.forename: M
authors.initials: M
authors.lastname: Kilian
mesh_terms: D000189:Actinobacillus Infections / Q000276:immunology / Q000382:microbiology*; D000293:Adolescent; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification* / Q000235:genetics / Q000276:immunology; D010520:Aggressive Periodontitis / Q000276:immunology / Q000382:microbiology*; D000907:Antibodies, Bacterial / Q000097:blood; D001427:Bacterial Toxins / Q000276:immunology; D016022:Case-Control Studies; D002999:Clone Cells; D004198:Disease Susceptibility / Q000276:immunology; D005098:Exotoxins / Q000276:immunology; D005884:Gingival Hemorrhage / Q000276:immunology / Q000382:microbiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000276:immunology; D009018:Morocco; D021141:Nucleic Acid Amplification Techniques; D017622:Periodontal Attachment Loss / Q000276:immunology / Q000382:microbiology; D010514:Periodontal Pocket / Q000276:immunology / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D005098:Exotoxins; D007166:Immunosuppressive Agents; D012336:RNA, Ribosomal, 16S; C018579:leukotoxin