Molecular epidemiology of Helicobacter pylori: separation of H. pylori from East Asian and non-Asian countries

Epidemiol Infect. 2000 Feb;124(1):91-6. doi: 10.1017/s0950268899003209.


The predominant H. pylori strain circulating among geographic locations differs with regard to the genomic structure. This study determined whether structural subtypes of the cagA 3' repeat region could be used to identify the population of origin of H. pylori isolates. We examined 600 cagA-positive H. pylori (Colombia, 100; USA, 100; France, 100; Canada, 20; Italy, 20; Korea, 100; Japan, 100; Hong Kong, 20; Taiwan, 20; Vietnam, 20). The cagA 3' region was amplified by PCR using primers specific to Japanese and Western 3' cagA gene sequences. PCR using Japanese cagA primers resulted in PCR products in 99-6 % of strains from East Asia but no non-Asian strains. Conversely, PCR using Western cagA primers resulted in amplicons in 100% of non-Asian strains, and only one from East Asia. cagA genotyping is useful for molecular epidemiological studies as strains can be completely separated by differences in the cagA 3' region.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Americas / epidemiology
  • Antigens, Bacterial*
  • Asia, Eastern / epidemiology
  • Bacterial Proteins / genetics*
  • Europe / epidemiology
  • Genotype
  • Helicobacter Infections / epidemiology*
  • Helicobacter pylori / genetics*
  • Humans
  • Middle Aged
  • Polymerase Chain Reaction
  • Repetitive Sequences, Nucleic Acid
  • Vietnam / ethnology


  • Antigens, Bacterial
  • Bacterial Proteins
  • cagA protein, Helicobacter pylori