[Molecular phylogeny analysis of full-length vacA and cagA genes from Helicobacter pylori].

All amino acid full-length sequences of VacA and CagA proteins from Helicobacter pylori strains including vacA and cagA genes were downloaded from GenBank. Molecular phylogenic trees of VacA and CagA were constructed by ClastalX 2.0 and MEGA 5.05 software to understand phylogenetic relationships of vacA and cagA genes, clinical infection effects, and genotype characteristics of different clustering groups. The results showed that the phylogenetic trees of VacA and CagA recapitulated the same three-clustering groups, i.e., East Asia group 1 and 2 and Western group, and all H. pylori strains had similar distribution. The strains of East Asia group 1 were significantly higher in patients with atrophic gastritis. Genotype vacA contained mainly s1c/m1b and s1a/m1b, while genotype cagA was mostly EPIYA-ABD. The strains of East Asia group 2 were higher in patients with duodenal ulcer. Genotype vacA was mainly s1c/m2 and s1a/m2, while genotype cagA was mostly EPIYA-AB'C. The strains of Western group were higher in patients with duodenal ulcer and chronic gastritis than with atrophic gastritis. Genotype vacA was mainly s1a/m1a and s1b/m1a, while genotype cagA was mostly EPIYA-AB/B'CC. All of these results illustrated that there might be inheritant relationship of coevolution between vacA and cagA genes; East Asia group 1 and 2 and Western group had different vacA and cagA sub-genotypes, which had close rela-tionship to its clinical infection effects. It might be necessary to deeply analyze vacA and cagA sub-genotypes in the re-search of H. pylori-related diseases.