Strain differentiation and phylogenic relationships, in terms of base sequence of the ure B gene, of Helicobacter pylori.

We constructed a phylogenetic tree based on the nucleotide sequence of the ure B gene of Helicobacter pylori strains, amplified by polymerase chain reaction (PCR). We analyzed the tree in terms of the relationship between the PCR-restriction fragment length polymorphism (RFLP)-genotype and the sequevar. The main frame of ure B (928 bp) was amplified by PCR from 38 strains of clinical isolates and reference species. The amplified probes were sequenced and processed into matrix and phylogenic trees. Homogeneity of the strains of "intra-case" origin and heterogeneity in "inter-cases" was parallel to clustering on the phylogenic tree. Sequevars in a cluster showed an identical RFLP-genotype in one case, indicating the clonal origin of H. pylori flora in an individual.