Cloning and sequence analysis of ureB gene of Helicobacter pylori / 中华微生物学和免疫学杂志

ABSTRACT

Objective　To determine the diversity of ureB gene of H. pylori for development of vaccines and evaluation of diagnostic kits by sequence analysis of ureB genes of 8 H. pylori. Methods　Primers were designed according to the sequence of strain 26695 and used to amplify the ureB gene of H. pylori (CAPM N62, CAMP N93, CAMP N98, CAMP F3). The PCR products were cloned into pGEM-T vector respectively and sequenced. The sequences of tested strains were compared with the corresponding regions of the GenBank strains (26695, J99, MD506, CPM630) and analyzed by DNA and Winstar software. Results　There are three kinds of length of ureB gene in all 8 strains. The lengths of ureB gene of CAMP F3 and CPM630 are 1269bp and 1680bp respectively. The others are 1710bp. The result of the sequence analysis of ureB gene of 6 strains of H. pylori with length of 1710bp indicated that the three foreign strains showed high homology in nucleotide acid and their homology were 100% in putative amino acid. The three domestic strains were closely related. Conclusions　As a potential protective antigen, ureB has the problem of variable coverage rate in different populations. In order to gain extensive coverage rate, it is important to find the antigen peptide of conservative ureB gene of H. pylori which is predominant in population.