background :the cag pathogenicity island includes a number of genes, including cytotoxin-associated protein a (caga) and vacuolatingcytotoxin (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...

BACKGROUND Gastric Helicobacter pylori colonization leads to iron deficiency anemia (IDA), especially in children and adolescents. However the pathogenesis is poorly understood. OBJECTIVE We sought to identify specific H. pylori genes involved in IDA development, by comparing bacterial genome-wide expression profiling in patients affected or not. METHODS H. pylori were isolated from four ch...

Helicobacter pylori vacuolating cytotoxin A (VacA) has been considered as an apoptosis-inducing factor. Here, we investigated the mechanism of VacA-induced apoptosis in relation to the defense mechanism and MAP kinases pathway in gastric epithelial cells. AGS cells exposed to enriched VacA extracts affected the level of SOD-1 and villin. We further investigated the role of VacA in those inducti...

More than 50% of the world's population is infected with Helicobacter pylori (H. pylori). Chronic infection with this Gram-negative pathogen is associated with the development of peptic ulcers and is linked to an increased risk of gastric cancer. H. pylori secretes many proteinaceous factors that are important for initial colonization and subsequent persistence in the host stomach. One of the m...

In this study, we describe the ultrastructural changes associated with acid activation of Helicobacter pylori vacuolating cytotoxin (VacA). Purified VacA molecules imaged by deep-etch electron microscopy form approximately 30-nm hexagonal "flowers," each composed of an approximately 15-nm central ring surrounded by six approximately 6-nm globular "petals." Upon exposure to acidic pH, these olig...

A number of pathogenic bacteria target mitochondria to modulate the host's apoptotic machinery. Studies here revealed that infection with the human gastric pathogen Helicobacter pylori disrupts the morphological dynamics of mitochondria as a mechanism to induce host cell death. The vacuolating cytotoxin A (VacA) is both essential and sufficient for inducing mitochondrial network fragmentation t...

AIM To investigate the association of gastric histological and endoscopic findings in patients with Helicobacter pylori (H. pylori), according to presence of seropositivity to 12 bacterial virulence antigens. METHODS This is a cross-sectional single-center study of 360 consecutive outpatients referred in the period of one year to upper gastrointestinal endoscopy because of dyspeptic complaint...

Virulence-associated genes and neutral DNA markers of Helicobacter pylori strains from the Santhal and Oroan ethnic minorities of West Bengal, India, were studied. These people have traditionally been quite separate from other Indians and differ culturally, genetically, and linguistically from mainstream Bengalis, whose H. pylori strains have been characterized previously. H. pylori was found i...

Two key virulence factors of Helicobacter pylori are the secreted virulent proteins of vacuolating toxin A (VacA) and cytotoxin associated protein A (CagA) which lead to damages of gastric epithelial cells. We previously identified that the cyanidin 3-O-glucoside (C3G) inhibits the secretion of both VacA and CagA. In the current report, we show that C3G inhibits VacA secretion in a dose-depende...

To investigate the kinetics and mechanisms of extracellular protein release by Helicobacter pylori, we analyzed the entry of metabolically radiolabeled bacterial proteins into broth culture supernatant. At early time points, vacuolating cytotoxin (VacA) constituted a major extracellular protein. Subsequently, culture supernatants accumulated many proteins that were components of intact bacteria...