USE OF THE POLYMERASE CHAIN-REACTION TO DETECT HELICOBACTER-PYLORI INTHE DENTAL PLAQUE OF HEALTHY AND SYMPTOMATIC INDIVIDUALS

A polymerase chain reaction (PCR) assay, based on the amplification of a species specific ureA (urease) gene internal sequence, was used to detect Helicobacter pylori. Total DNA extracts were obtained from dent al plaque in patients attending an endoscopy clinic and from apparentl y healthy schoolchildren of Bangladeshi origin. Of the 54 samples of d ental plaque from endoscopy patients examined, 39 were positive (72 pe r cent). There was 63 per cent correlation (34/54) between H. pylori i n the stomach and apparent H. pylori in dental plaque. Seventy-four pe r cent (29/39) of gastric biopsy culture positive individuals were den tal plaque PCR positive. Nine patients had positive plaque PCR, but we re negative for gastric culture. In asymptomatic schoolchildren, 58 pe r cent (11/19) had positive dental plaque PCR results. The results sug gest that H. pylori is present in dental plaque at high frequency and PCR of dental plaque may provide a strategy for studying transmission of H. pylori.