Phenotypic and genotypic characterization of Helicobacter pylori from patients with and without peptic ulcer disease

Background: Helicobacter pylori plays an important role in peptic ulcer dis ease, although not all H. pylori-infected persons will develop a peptic ulc er. Currently, H. pylori strains cannot be divided into commensals and path ogens. Methods: Fifty H. pylori strains were cultured from patients divided into five groups on the basis of upper endoscopic findings: gastric ulcer, duodenal ulcer, gastritis, esophagitis, or normal. The ultrastructural adh erence pattern in vivo, autoagglutination, hemagglutination, adhesion to hu man gastric adenocarcinoma (AGS) cells, and the lipopolysaccharide (LPS) pr ofile of H. pylori strains were recorded randomly amplified polymorphic DNA (RAPD) and urease gene typing were performed and correlated with diagnosti c groups. Results: Electron micrographs showed that H. pylori strains from patients with gastric ulcers adhered more frequently through filamentous st rands and were less frequently found free in mucus than any other diagnosti c group (P < 0.0001). Neither median hemagglutination titer nor median adhe sion capacity to a human gastric adenocarcinoma cell line was related to en doscopic findings. Nevertheless, H. pylori strains from patients with gastr ic ulcers were more prone to autoagglutinate than were strains from the oth er diagnostic groups (P = 0.03). H. pylori strains from gastric nicer patie nts were found to be more homogeneous, as determined by RAPD and urease gen e typing, than strains from the other diagnostic groups (P < 0.01). In addi tion, a positive correlation was found between a patient's age and the adhe sion to AGS cells of the patient's H. pylori strain (P = 0.006). Conclusion : A combination of an H. pylori autoagglutination test, RAPD, and urease ge ne typing may be useful in separating gastric ulcer-related strains from du odenal ulcer-related and non-ulcer dyspepsia-related strains.