Genotyping and Molecular Epidemiology of Helicobacter pylori Strains Isolated from Korea

ABSTRACT

This study aims to know cagA and vacA genotypes and the molecular epidemiology of H. pylori strains isolated from patients with gastroduodenal disorders and normal healthy persons of Korea using PCR genotyping, RAPD fingerprinting, and PCR-RFLP. PCR genotyping for cagA genotyping showed that 143 H. pylori isolates tested in this study were cagA positive strains. All the isolates were confirmed as type sla genotype and 13 isolates (9%) among of 143 strains were confirmed as containing the RS2 element. All 143 isolates showed individually unique RAPD profiles. PCR-based RFLP was done to assess the sequence diversity of H. pylori flagella genes. From all H. pylori isolates, 30 distinct patterns were found with HhaI digestion of 1.5 kb flaA segment and 12 distinct patterns were produced with MboI digestion. Among 30 persons, from whom multiple isolates could be obtained, 27 (90%) were confirmed to be colonized with an identical H. pylori strain and 3 (10%) were shown to be infected with the different strains. Among 5 persons attended in follow-up study, 4 were infected with identical strain for 1 year, 1 carried different strains after 1 year. Genotypes of isolates recovered from children were shown to be identical to those of their parents, suggesting that children acquire H. pylori infection from their parents.