Genotyping CagA, VacA subtype, IceA1, and BabA of Helicobacter pylori isolates from Korean patients, and their association with gastroduodenal diseases

The genetic status of cagA, vacA subtype, iceA1, and babA, and the relation ship to gastroduodenal diseases were assessed in Helicobacter pylori isolat es in Korea. Seventy-six strains of H. pylori were isolated from the antrum and the corpus of 41 adult patients (22 with peptic ulcer and 19 with gast ritis). The cagA, iceA1, and babA genes were assessed by polymerase chain r eaction and the vacA subtypes were determined by reverse hybridization-line probe assay. The positive rates of 349-bp cagA, 208-bp cagA, iceA1, and ba bA genes were 97.4%,96.1%,84,2%, and 36.1%, respectively. The vacA s1a, s1b , s1c, and s2 variants were detected in 11.8%, 3.9%, 80.4%, and 1.3%, respe ctively. ml (78.9%) is more prevalent than m2 (5.3%). The most common vacA genotype was s1c/m1 (61.9%), and 14 isolates (18.4%) contained mixed vacA g enotypes from a single biopsy specimen. Twenty-one (60%) of 35 patients wer e infected with more than two strains of different cagA, iceA1, babA, and v acA genotypes. None of cagA, iceA1, babA, and vacA s1/m1 were associated wi th peptic ulcer. In conclusion, most H. pylori isolates in Korea carry cagA , iceA1, and vacA s1c/m1 genes, and reside with multiple strains. These gen es do not correlate with the peptic ulcer in the Korean patients.