BACKGROUND The cytotoxin associated gene A (cagA), and the vacuolating cytotoxin gene A (vacA) of Helicobacter pylori have been associated to phenotypic characteristics of virulence. The objectives of this study were to detect the presence of cagA and to characterize the allelic variants of vacA in 63 strains of H. pylori isolated from colonized individuals with different clinical outcomes. M...

Polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells were used to study the pathogenicity of Helicobater pylori, with an emphasis on the effect of VacA. The adherence of H. pylori to MDCK monolayers resulted in a decrease in trans-epithelial resistance (TER) across the cell monolayer. Isogenic vacA mutants did not lower the TER, demonstrating that the effect is strictly lin...

objective: helicobacter pylori is a major etiological agent in gastro-duodenal disorders, and has spread in the world. the prevalence of infection with h. pylori is more than 80% in some populations, but only 10% to 20% of them are infected with this organism. also infection with this pathogen is associated with peptic ulcer disease (pud), gastritis (g), duodenitis (du), and non-ulcer dyspepsi...

background: helicobacter pylori strains have two classical virulence genes, the cytotoxinassociated a ( caga ) gene and the vacuolating cytotoxin a ( vaca ) gene, which are located in the cag pathogenicity island ( cag pai). serum immunoglobulin g (igg) antibodies to h. pylori , especially, the caga antigen may be a reliable marker for selection of dyspeptic patients for upper endoscopy. method...

BACKGROUND homB encodes a Helicobacter pylori outer membrane protein. This gene was previously associated with peptic ulcer disease (PUD) and was shown to induce activation of interleukin-8 secretion in vitro, as well as contributing to bacterial adherence. Its 90%-similar gene, homA, was previously correlated with gastritis. The present study aimed to evaluate the gastric disease association w...

background and objective: helicobacter pylori has several strains with different degrees of virulence. the aim of this study was to detect two major important virulence factors, caga/vaca genotypes, and to determine correlations among different caga/vaca genotypes and histological features of chronic gastritis in iranian patients. methods: in this cross- sectional study, gastric biopsy was take...

VacA is a secreted toxin that plays a role in Helicobacter pylori colonization of the stomach and that contributes to the pathogenesis of peptic ulcer disease. Studies of VacA structure and function have been hindered by the lack of an efficient system for expression and genetic manipulation of this toxin. In this study, we developed methodology for expression of a functionally active VacA toxi...

Helicobacter pylori is a bacterial pathogen evolved to chronically colonize the gastric epithelium, evade immune clearance by the host, and cause gastritis, peptic ulcers, and even gastric malignancies in some infected humans. In view of the known ability of this bacterium to manipulate gastric epithelial cell signal transduction cascades, we determined the effects of H. pylori infection on epi...