Genotypes of the Helicobacter pylori vacA Signal Sequence Differ with Age in Korea

Background. Studies on Helicobacter pylori genotypes have focused on adults in developed countries, and data on the genotypes of Helicobacter pylori recovered from the children are rare. Materials and methods. One hundred and twenty-eight biopsy samples from patients with H. pylori infection were studied. The patients' ages ranged from 9 to 83 years. PCR analysis for vacA genotypes was performed using DNA extracted from biopsy specimens. Results. Genotyping of the s-region showed s1a in 33 (25.8%) samples and s1c in 82 (64.1%) samples. When the specimens were grouped by age, the distribution of s-region genotype was found to be significantly different between groups (p = .002). The prevalence of s1a was 45.2% in patients < 20 years old, but 14.9% in patients ≥ 50 years old. On the other hand, the prevalence of s1c or recombinant s1a-s1c was higher in those ≥ 50 years old. The distribution of the m-region did not differ significantly with age (p =.110). Conclusions. Strain populations infecting Korean adults and children differ.