DEVELOPMENT OF A RAPID PCR METHOD FOR IDENTIFICATION OF HELICOBACTER-PYLORI IN DENTAL PLAQUE AND GASTRIC BIOPSY SPECIMENS

A rapid and simple polymerase chain reaction (PCR) method was develope d to detect Helicobacter pylori in gastric biopsy specimens and dental plaque samples. The primers were targeted to the 16S rRNA sequence of Helicobacter pylori strain ATCC 43504. The system was found to have a theoretical detection level of 0.5 to 5 Helicobacter pylori cells in a 5 mu l Sample of dental plaque. In the absence of plaque, the detect ion level was even better: theoretically, 0.05 to 0.5 Helicobacter pyl ori cells were detected in water suspension. However, this appeared to be due to the presence of free bacterial DNA in the culture used for the sensitivity determination. Thus, the actual sensitivity of the sys tem was found to be fewer than five Helicobacter pylori cells, irrespe ctive of the type of sample used. The method was then used to analyse 29 dental plaque and gastric biopsy specimens collected from patients with a history of recurrent peptic ulcer disease. Fourteen stomach spe cimens were positive for Helicobacter pylori when tested with the PCR method, while the respective figures with culture, histological examin ation and the urease test were 11, 12 and 9. No positive dental plaque samples were observed.