COMBINATION OF SINGLE-STRANDED AND DOUBLE-STRANDED CONFORMATIONAL POLYMORPHISM FOR DIRECT DISCRIMINATION OF GASTRIC HELICOBACTER-PYLORI

Molecular typing of strains among the highly diverse population of Hel icobacter pylori (H. pylori) is an important approach for both basic a nd clinical studies. Genomic DNAs prepared from 18 gastric biopsy spec imens, 21 H. pylori clinical isolates obtained from gastric biopsy spe cimens, and five isolates collected from a single patient at weekly in tervals, were subjected to a combined single- and double-stranded conf ormational polymorphism (SDSCP) assay. The results showed that 19 of 2 1 isolates tested were discriminated by SDSCP analysis. SDSCP analysis of five H. pylori isolates collected from the same patient at differe nt times resulted in five identical profiles, suggesting the reproduci bility of the method. When DNA preparations from 18 gastric biopsy spe cimens were subjected to SDSCP analysis, 18 unique profiles were gener ated that matched those of their corresponding cultured H. pylori isol ates from each patient. For comparison, polymerase chain reaction (PCR )-based restriction fragment length polymorphism analysis yielded only nine profiles for 20 strains. The data suggest that SDSCP analysis ma y be an effective and reliable method for differentiation of H. pylori strains directly from gastric biopsy specimens without requiring isol ation of the organisms by culture. (C) 1998 Published by Elsevier Scie nce B.V. All rights reserved.