AIM To examine the vacA genotypes of Helicobacter pylori strains in Japan and to define whether any specific genotype was associated with gastric cancer. METHODS The allelic variation of vacA gene was studied using a recently introduced polymerase chain reaction based vacA genotyping system. RESULTS 80 H pylori strains were isolated from gastric biopsies of 40 patients with gastric cancer a...

PURPOSE Virulent genotypes of Helicobacter pylori vacA s1m1/cagA+/babA2+ have been associated with severe gastric diseases. VacA, CagA and BabA are polymorphic proteins, and their association with the disease is allele-dependent. The aims of this work were: (i) to determine the prevalence of H. pylori by type of chronic gastritis; (ii) to describe the frequency of cagA, babA2 and vacA genotypes...

20 yr have elapsed since the discovery of the association of the then novel bacterium Helicobacter pylori with different gastroduodenal diseases, including severe active chronic gastritis, gastroduodenal ulcers, adenocarcinoma, and lym-phoma (1). The amount of research performed from the clinical to the molecular level is impressive (2). It is presently well established that H. pylori infects t...

BACKGROUND The pathogenic mechanisms involved in Helicobacter pylori-induced duodenal mucosal injury are incompletely understood. In the present study, we sought to investigate the effect of H. pylori vacuolating cytotoxin (VacA) on duodenal mucosal bicarbonate (HCO3-) secretion. METHODS Concentrated bacterial culture supernatants from an H. pylori wild-type strain producing VacA with s1/m1 g...

We have examined the prevalence of gene cagA and vacA alleles in 129 patients, 69 with gastritis and 60 with peptic ulcer diseases from North Brazil and their relation with histopathological data. vacA and cagA genotype were determined by polymerase chain reaction. Hematoxylin-eosin staining was used for histological diagnosis. 96.6% of the patients were colonized by Helicobacter pylori strains...

BACKGROUND Helicobacter pylori infection and related diseases outcome are mediated by a complex interplay between bacterial, host and environmental factors. Several distinct virulence factors of H. pylori have been shown to be associated with different clinical outcomes. Here we focused on vacA and cagA genotypes of H. pylori strains isolated from patients with gastric disorder. OBJECTIVES Th...

BACKGROUND Studies in Western populations suggest that cagA, iceA, and vacA gene status in Helicobacter pylori isolates is associated with increased virulence and peptic ulcer disease. AIM To investigate the relationship between peptic ulcer and expression of Lewis (Le) antigens as well as cagA, iceA, and vacA in H pylori isolates in Singapore. METHODS Expression of Le antigens in H pylori ...

Analysis of 12 Helicobacter pylori promoters indicates the existence of a consensus -10 hexamer (TAtaaT) but little conservation of -35 sequences. In this study, mutations in either the H. pylori vacA -10 region or the -35 region resulted in decreased vacA transcription and suggested that an extended -10 motif is utilized. Thus, despite the lack of a -35 consensus sequence for H. pylori promote...

Helicobacter pylori is the etiological agent of diseases such as gastritis, gastric and duodenal ulcers, and two types of gastric cancers. While some insight has been gained into the etiology of these diverse manifestations, by and large, the reason that some individuals develop more severe disease remains elusive. Recent studies have focused on the roles of H. pylori toxins CagA and VacA on th...

The effects of the vacuolating toxin (VacA) released by pathogenic strains of Helicobacter pylori on several polarized epithelial monolayers were investigated. Trans-epithelial electric resistance (TER) of monolayers formed by canine kidney MDCK I, human gut T84, and murine mammary gland epH4, was lowered by acid-activated VacA. Independent of the cell type and of the starting TER value, VacA r...