pylori virulence and that the mechanism underlying the involvement of HomB in inflammation is bacterial adherence. CP673451 supplier The present study aimed to explore

the distribution of homB and homA genes in different geographical regions. Moreover, no information on homB and homA allelic variation at the population level is available to date. Thus, to better understand the diversity and evolution of these two H. pylori OMP-coding genes, both comparative and phylogenetic sequence analyses were performed, using H. pylori strains with a different geographical background. Results Distribution of homB and homA genes in H. pylori strains isolated from different countries The buy AZD5582 presence of homB and homA genes in the H. pylori clinical strains was determined by a single PCR with a set of primers designed on a consensus internal sequence present in both genes, which generates PCR products of 161 bp and 128 bp for homB and homA, respectively. A PCR product of one of these sizes was obtained for 449 out of 455 strains tested, suggesting selleck inhibitor that one of these genes is always present in the H. pylori genome. However, in six remaining cases, PCR fragments of an intermediate length were observed (146 bp for four Korean and one French strain and 152 bp for one Japanese strain), which does not relate to either the homB or the homA genotype. Although phylogenetic analysis of these PCR fragments

showed that these particular sequences were closer to homB gene, those of the discriminating region (from 470 to 690 bp) and the entire gene (GenBank accession numbers EU910189 to EU910194) did not show a higher similarity with either homB Tolmetin or homA, instead the sequences were grouped by geographic origin (data not shown). These sequences were excluded from further analysis. Analysis of the distribution of homB and homA genes in the H. pylori clinical strains (n = 449) from the different countries studied revealed that both genes were equally distributed among Western countries (n = 300, 56.0% for homB and 60.4% for homA). homA

was found slightly more frequently than homB in strains from Portugal (n = 115, 66.5% vs 49.7%), France (n = 34, 58.9% vs 46.7%), Sweden (n = 27, 58.6% vs 41.5%), USA (n = 29, 72.4% vs 53.4%) and Brazil (n = 56, 73.4% vs 62.4%), while homB was more frequently found in strains from Germany (n = 20, 60% vs 45%) and Colombia (n = 19, 67.8% vs 42.8%). Among strains from East Asian countries (n = 138), homB was highly frequent in both Japan and Korea (n = 71, 95.9% and n = 67, 77.2%, respectively), while homA was more rare (5.9% and 21.2%, respectively). In strains from Burkina Faso (n = 11), both genes were highly frequent (90.9%). Diversity of homB and homA genes Considering the numbering of the J99 strain, the homA and homB genes are localized at the jhp0649 locus (locus A) and the jhp0870 locus (locus B), respectively [13].