New Rapid Polymerase Chain Reaction‐Immunochromatographic Assay for Porphyromonas gingivalis

• Published in: Journal of periodontology (1970) 2005-04, Vol.76 (4), p.508-512
• Main Authors: Takada, Kazuko, Sakaguchi, Yoshiaki, Oka, Chitoshi, Hirasawa, Masatomo
• Format: Article
• Language: English
• Subjects: Bacterial Typing Techniques; Chromatography - methods; Colony Count, Microbial; Dentistry; DNA, Bacterial - analysis; Gingival Crevicular Fluid - microbiology; Humans; Immunochromatographic assay/instrumentation; Periodontitis - microbiology; polymerase chain reaction; Polymerase Chain Reaction - methods; Porphyromonas gingivalis; Porphyromonas gingivalis - genetics; Porphyromonas gingivalis - isolation & purification; Sensitivity and Specificity
• ISSN: 0022-3492; 1943-3670
• DOI: 10.1902/jop.2005.76.4.508

Background: A simple and rapid method for Porphyromonas gingivalis detection in clinical samples has been developed using polymerase chain reaction (PCR) and an immunochromatographic assay (ICA) with a lateral‐flow device (strip) to detect species‐specific 16S rRNA genes. Methods: The PCR used a pair of primer sets labeled with fluorescein isothiocyanate (FITC) or biotin at each 5' terminus. The strip used a nitrocellulose membrane containing streptavidin conjugated to gold particles and anti‐FITC line. Results: PCR and ICA detected as few as 1 and 10 cells of P. gingivalis, respectively. ICA required 5 to 10 minutes more than the initial PCR. The amplifications were not observed in other oral black‐pigmented bacteria at concentrations of 106 colony forming unit (CFU). The ICA strips showed bands at more than 104 CFU/ml equivalents in clinical samples from periodontitis. Conclusions: A diagnostic assay based on PCR‐ICA was developed for the detection of P. gingivalis, and results were obtained visually in 3 hours. PCR‐ICA will be a valuable tool for the rapid detection of target bacteria by chair side. J Periodontol 2005;76:508‐512.