Naturally occurring noncytotoxic vacA type s2 strains of Helicobacter pylori have a 12-residue extension to the vacuolating cytotoxin (VacA) compared with cytotoxic type s1 strains. We show that adding the region encoding this extension to type s1 vacA completely abolishes vacuolating cytotoxin activity but has no effect on VacA production.

Approximately 50% of Helicobacter pylori strains produce a cytotoxin that is encoded by vacA and that induces vacuolation of eukaryotic cells. Mosaicism in vacA alleles was reported, and there are three different families of vacA signal sequences (s1a, s1b, and s2) and two different families of middle-region alleles (m1 and m2). In addition, the vacA genotype of a strain is associated with its ...

The vacuolating cytotoxin and the cytotoxin-associated protein, encoded by vacA and cagA, respectively, are important virulence determinants of Helicobacter pylori. Sixty-five H. pylori strains were isolated from dyspeptic patients (19 with peptic ulcer disease, 43 with chronic gastritis, and 3 with gastric cancer) and studied for differences in the vacA and cagA genes and their relationship to...

BACKGROUND It has been reported that infection with vacuolating cytotoxin positive Helicobacter pylori strains is associated with gastroduodenal disease in Western countries. AIMS To evaluate the prevalence of cytotoxin producing strains among patients with H pylori infection in relation to gastrointestinal diseases in Japan. PATIENTS Ninety seven patients undergoing endoscopy. METHODS A ...

Helicobacter pylori is the leading bacterial cause of food-borne illness worldwide and plays a major role in the development of chronic gastritis, peptic ulcer, and gastric cancer. Strains isolated from patients contain the cagA gene (cytotoxin-associated gene A) and produce the vacuolating cytotoxin, VacA. Recent molecular and cellular studies of VacA action have begun to unravel its structure...

BACKGROUND VacA and CagA proteins have been reported to be major virulence factors of Helicobacter pylori. However, antibodies against these proteins are frequently found in the sera of Japanese patients regardless of their gastroduodenal status. AIM To evaluate the expression of VacA and CagA proteins by H pylori strains isolated in Japan. METHODS By using specific antibodies raised agains...

The vacuolating cytotoxin (VacA) is a major virulence factor of Helicobacter pylori which is not yet well characterised and is difficult to obtain in large quantities. Here we describe the production of a monoclonal antibody that recognises the native but not the denatured form of VacA. The antibody can be efficiently used in affinity chromatography for one-step purification of large quantities...

Helicobacter pylori, which is involved in the pathogenesis of gastroduodenal disease, produces CagA and VacA as major virulence factors. CagA is classified into East Asian and Western types based on the number and sequences of its Glu-Pro-Ile-Tyr-Ala motifs. The vacA gene has three polymorphic regions: the signal (s), intermediate (i), and middle (m) regions. The lowest gastric cancer mortality...

Helicobacter pylori bacteria colonize the human stomach where they stimulate a persistent inflammatory response. H. pylori is considered noninvasive; however, lipopolysaccharide (LPS)-enriched outer membrane vesicles (OMV), continuously shed from the surface of this bacterium, are observed within gastric epithelial cells. The mechanism of vesicle uptake is poorly understood, and this study was ...

The Helicobacter pylori vacuolating cytotoxin (VacA) is a secreted pore-forming toxin and a major virulence factor in the pathogenesis of H. pylori infection. While VacA is present in almost all strains, only some forms are toxigenic and pathogenic. While vacA and its genotypes are considered as markers of H. pylori-related diseases or disorders, the pathophysiological mechanisms of VacA and it...