Single and Multiple Strain Colonization in Patients with Helicobacter pylori Associated Gastritis: Detection by Macrorestriction DNA Analysis

Helicobacter pylori</it> isolates from 18 patients were examined by macrorestriction DNA analysis to determine whether >2 strains can coexist in the human stomach. Four biopsy samples from different sites in each patient's stomach were cultured, and 12-14 clones of H. pylori</it> per patient were analyzed. DNA of 15 of the 18 isolates was digestible: 12 by NotI</it> and 3by NruI.</it> Within 14 of these digestible isolates, the patterns of all clones were identical. The isolate of 1 patient showed two digestion patterns, a finding that was confirmed by arbitrary primer polymerase chain reaction. The typeable isolates of all patients, except 2 who underwent gastroscopy on the same day, differed markedly from each other. These results indicate a noticeable discrepancy between the pronounced interpatient heterogeneity and the rare intrapatient variation of H. pylori.</it>