title: Quantification of periodontopathic bacteria in saliva using the invader assay.
abstract: When quantifying periodontopathic bacteria, it is important to use a convenient method that  does not produce false negative results. The Invader assay is a convenient method because it does not involve  gene amplification. The purpose of this study was to evaluate the validity of the Invader assay to quantify  periodontopathic bacteria. The Invader technology was applied in quantifying five periodontopathic bacteria  (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia,  and Treponema denticola). The Invader assay produced a linear quantitative detection range over concentrations  spanning seven exponential values, with a detection limit of 10(3.7) copies/tube and intra-day and inter-day  variance of 0.1% to 4.7% and 0.1% to 3.4%, respectively, in quantifying five periodontopathic bacteria. We  compared the results of the Invader assay with those of real-time polymerase chain reaction (PCR) performed for  quantifying five periodontopathic bacteria in 22 patients with periodontitis. Among the Invader-detectable  bacterial strains of each species, significant correlations were observed in the counts of concerned bacterial  species between these two methods, with correlation coefficients ranging from 0.757 to 0.996. This study  validated repeatability and reproducibility of the Invader assay in quantifying periodontopathic bacteria and  demonstrated consistent agreement between the Invader assay and real-time PCR in quantifying periodontopathic  bacteria.
authors.affiliation: Department of Health Science, Hyogo University, Hyogo, Japan. atada@hyogo-dai.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Tada
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Hajime
authors.initials: H
authors.lastname: Shimizu
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tadokoro
authors.forename: Kazuya
authors.initials: K
authors.lastname: Tanaka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kawamura
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Toru
authors.initials: T
authors.lastname: Egashira
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nomura
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hanada
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D060005:Genotyping Techniques / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing / Q000379:methods*; D010518:Periodontitis / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D012463:Saliva / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial