IDENTIFICATION OF HELICOBACTER-PYLORI DNA IN THE MOUTHS AND STOMACHS OF PATIENTS WITH GASTRITIS USING PCR

Aims-To determine the prevalence of Helicobacter pylori colonisation i n the mouths of patients with H pylori gastritis. Methods-A nested pol ymerase chain reaction test for the 16S ribosomal RNA gene of H pylori was used on saliva, dental plaque, gastric juice and gastric biopsy s pecimens from patients attending a dyspepsia clinic. Results-Thirteen patients had histologically confirmed Helicobacter associated gastriti s. Twelve of these had positive gastric aspirates by PCR. Five had at least one positive oral specimen. Eight patients with normal gastric b iopsy specimens had no PCR positive oral specimens or gastric aspirate s. All, however, had PCR positive gastric biopsy specimens. In an atte mpt to determine the origin of these positive results in normal patien ts, it was shown that biopsy forceps could contaminate specimens with DNA from previous patients. Conclusion-The demonstration of the organi sm in the mouths of a substantial proportion of dyspeptic patients has major implications for the spread of H pylori and identifies a potent ial source for reinfection following eradication of the organism from the stomach.