UNLABELLED Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. MATERIALS AND METHODS The antigenic ...

AIM To determine the virulence attributes (presence of cagA and vacA genes) of Helicobacter pylori , and presence of clarithromycin resistance genes in gastric mucosal biopsy samples obtained in the United Arab Emirates. METHODS DNA was extracted from antral gastric biopsy samples from 91 dyspeptic patients. Real-time PCR and melting curve analysis were used to identify patients infected with...

Mosaicism in vacA alleles with two distinct families of vacA signal sequences (s1 and s2) and two distinct families of middle region alleles (m1 and m2) has been reported. Research suggests that the vacA s1 genotype is closely associated with duodenal ulcer disease and with high cytotoxin production. The aims of this study were to evaluate the role of vacA genotyping with respect to gastric inf...

Helicobacter pylori-produced cytotoxin VacA induces intracellular vacuolation. The VacA-induced vacuole is assumed to represent the pathological status of intracellular trafficking. The fusion mechanism of the endosomes requires the formation of a tight complex between the Q-SNAREs and the R-SNAREs. We recently reported that syntaxin 7, a family member of the Q-SNARE protein, is involved in Vac...

In this study we investigated the roles of lipid rafts and glycosylphosphatidylinositol-anchored proteins (GPI-APs) in the process of VacA binding and internalization into epithelial cells. Vacuolating activity analysis in AGS, CHO cells, and a CHO-derived line that highly expresses GPI-linked fasI proteins indicated the significance of cholesterol and GPI-APs for VacA activity. Flow cytometric...

OBJECTIVE To detect the presence of virulence markers cytotoxin-associated (cagA) and vacuolating cytotoxin-associated (vacA) genes in gastric biopsy specimens of patients with gastroduodenal disorders. METHODS This study was conducted at the Department of Pathology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between March 2008 and February 2009. A total of 118 gastric b...

Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gastric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA ...

Helicobacter pylori isolates vary between geographic regions. Certain H. pylori genotypes may be associated with disease outcome. Thirty-eight children underwent diagnostic upper endoscopy at four medical centers and were retrospectively analyzed to determine if H. pylori virulence genes were associated with endoscopic disease severity, histologic parameters, and host demographics. The H. pylor...

BACKGROUND The cag pathogenicity island includes a number of genes, including cytotoxin-associated protein A (cagA) and vacuolating cytotoxin (vacA) genotypes, which are associated with bacterial virulence. Although the role of cagA and vacA in the virulence of Helicobacter pylori (H. pylori) is well-established in epidemiological studies, the relationship between the cagA and vacA genotypes in...

By modulating important properties of eukaryotic cells, many bacterial protein toxins highjack host signalling pathways to create a suitable niche for the pathogen to colonize and persist. Helicobacter pylori VacA is paradigm of pore-forming toxins which contributes to the pathogenesis of peptic ulceration. Several cellular receptors have been described for VacA, which exert different effects o...