A clinico-epidemiological analysis of Helicobacter pylori (H. pylori) by Southern blotting with A urease gene probe.

Helicobacter pylori (H. pylori) is a gram-negative bacillus thought to be involved in such diseases of the upper gastrointestinal tract as gastritis, peptic ulcers, and gastric cancer. Urease is regarded as the factor responsible for the pathogenic nature of this bacterium. Therefore, in our examination of the genetic polymorphism of H. pylori, by means of Southern blotting, we used the urease gene as a probe. The Southern blot patterns of H. pylori isolated from different patients differed greatly, the inter-individual variation being so marked that it allowed approximate distinction between individual patients. The Southern blot patterns of individual strains of H. pylori did not change, even when they were stored and passed from generation to generation in our laboratory. These results suggest that DNA fingerprints with a urease gene probe will be useful in epidemiologically tracing H. pylori infection. Almost all strains of H. pylori isolated from different sites in the stomach of a patient on different occasions showed the same pattern, allowing us to confirm that only one strain of H. pylori was responsible for H. pylori infection in individual patients.