title: Quantitative molecular detection of putative periodontal pathogens in clinically healthy and periodontally diseased subjects.
abstract: Periodontitis is a multi-microbial oral infection with high prevalence among adults. Putative oral pathogens are commonly found in periodontally diseased individuals. However, these organisms can be also detected in the oral cavity of healthy subjects. This leads to the hypothesis, that alterations in the proportion of these organisms relative to the total amount of oral microorganisms, namely their abundance, rather than their simple presence might be important in the transition from health to disease. Therefore, we developed a quantitative molecular method to determine the abundance of various oral microorganisms and the portion of bacterial and archaeal nucleic acid relative to the total nucleic acid extracted from individual samples. We applied quantitative real-time PCRs targeting single-copy genes of periodontal bacteria and 16S-rRNA genes of Bacteria and Archaea. Testing tongue scrapings of 88 matched pairs of periodontally diseased and healthy subjects revealed a significantly higher abundance of P. gingivalis and a higher total bacterial abundance in diseased subjects. In fully adjusted models the risk of being periodontally diseased was significantly higher in subjects with high P. gingivalis and total bacterial abundance. Interestingly, we found that moderate abundances of A. actinomycetemcomitans were associated with reduced risk for periodontal disease compared to subjects with low abundances, whereas for high abundances, this protective effect leveled off. Moderate archaeal abundances were health associated compared to subjects with low abundances. In conclusion, our methodological approach unraveled associations of the oral flora with periodontal disease, which would have gone undetected if only qualitative data had been determined.
authors.affiliation: Friedrich Loeffler Institute of Medical Microbiology, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Göhler
authors.affiliation: Friedrich Loeffler Institute of Medical Microbiology, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Hetzer
authors.affiliation: Unit of Periodontology, Dental School, University Medicine, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Holtfreter
authors.affiliation: Unit of Periodontology, Dental School, University Medicine, Ernst Moritz Arndt University, Greifswald, Germany; Institute for Medical Informatics, Biometry and Epidemiology (IMIBE), University Hospital of Essen, University of Duisburg-Essen, Essen, Germany.
authors.forename: Marie Henrike
authors.initials: MH
authors.lastname: Geisel
authors.affiliation: Section Methods in Community Medicine, Institute for Community Medicine, University Medicine Greifswald, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: Carsten Oliver
authors.initials: CO
authors.lastname: Schmidt
authors.affiliation: Friedrich Loeffler Institute of Medical Microbiology, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: Ivo
authors.initials: I
authors.lastname: Steinmetz
authors.affiliation: Unit of Periodontology, Dental School, University Medicine, Ernst Moritz Arndt University, Greifswald, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kocher
mesh_terms: D000328:Adult; D001105:Archaea / Q000235:genetics*; D001419:Bacteria / Q000235:genetics*; D015169:Colony Count, Microbial; D019295:Computational Biology; D005260:Female; D005858:Germany; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009696:Nucleic Acids / Q000032:analysis*; D009841:Oligonucleotides / Q000235:genetics; D010518:Periodontitis / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013045:Species Specificity
chemical_list: D009696:Nucleic Acids; D009841:Oligonucleotides; D012336:RNA, Ribosomal, 16S