PT  - JOURNAL ARTICLE
AU  - Q Song
AU  - B Haller
AU  - D Ulrich
AU  - A Wichelhaus
AU  - G Adler
AU  - G Bode
TI  - Quantitation of <em>Helicobacter pylori</em> in dental plaque samples by competitive polymerase chain reaction
AID  - 10.1136/jcp.53.3.218
DP  - 2000 Mar 01
TA  - Journal of Clinical Pathology
PG  - 218--222
VI  - 53
IP  - 3
4099  - http://jcp.bmj.com/content/53/3/218.short
4100  - http://jcp.bmj.com/content/53/3/218.full
SO  - J Clin Pathol2000 Mar 01; 53
AB  - Aim—To establish a competitive PCR (cPCR) assay for quantitation of H pylori organisms in dental plaque samples. Methods—The cPCR coamplified target H pylori DNA and a known amount of internal standard template in the same tube with the same primers directed to 0.86 kb DNA of H pylori. The internal standard was a synthesised DNA bearing the same primer recognition sites at two ends and a non-homologous core sequence as the target DNA fragment. Quantitation was based on determination of the relative, not absolute, amounts of the differently sized and [32P]-dCTP labelled products derived from H pylori DNA and the competitive internal standard after gel electrophoresis separation. Results—A significant correlation between known amounts of H pylori added to dental plaque samples and the results of the cPCR was found, and a standard line was developed which allowed quantitation of H pylori in the plaque samples. cPCR was performed on supragingival plaque samples from 10 adult patients with H pylori infection in the stomach, and from five adults and six children without H pylori infection in the stomach. The ranges of H pylori numbers were 1–213 (median 25), 6–76 (10), and 4–94 (14) cells/mg of dental plaque in the three groups, respectively. Conclusions—cPCR is useful for quantitation of H pylori in supragingival dental plaque samples; however, the number of the organisms in dental plaque samples seems very low.