[Genetic heterogeneity of helicobacter pylori putative virulence genes and association with clinical outcomes, recent studies and future perspectives]

Helicobacter pylori [H. pylori] plays an important role in the development of peptic and duodenal ulcerations as well as gastric cancer. Several studies have shown a strong association between specific genotypes of H. pylori and gastrointestinal tract diseases. The vacA and cagA genes, which are the putative virulence factors of the bacterium, are important determinants of H. pylori-related diseases. Polymorphisms of the signal peptide [s], middle [m], and intermediate [i] regions of the vacA gene, presence of the cagA, and genetic heterogeneity of the C-terminal motifs of CagA might result in varying clinical outcomes in H. pylori-infected patients. In this review article, the intracellular activities of VacA and CagA proteins, the genetic diversity of the coding sequences of these proteins, their association with clinical outcomes with regard to the status of H. pylori infection in Iran, and future perspectives are discussed

[Neutralization of helicobacter pylori cytotoxicity on vero cells by omeprazole]

Omeprazole is a gastric parietal cells proton pump inhibitor that is also active against H. pylori in vitro. This study was designed to examine the neutralization of H. pylori cytotoxicity on Vero cells by omeprazole micronized in strains isolated from gastritis, ulcer, cancer and Barrett's ulcer, to determine whether omeprazole can inhibit vacuolation of the Vero cells induced by cytotoxin of H. pylori or by urease. The effect of omeprazole on motility of H. pylori was assessed using concentrations lower than MIC. The antimicrobial activity of omeprazole micronized was studied by determining the MICs for 15 H. pylori strains. Water extract of the bacteria [concentrated culture supernatant] and different concentrations of omeprazole were added to Vero cells in culture. Also extracted urease from H. pylori strains with urea [10 mM] and omeprazole were added to Vero cells in culture. The inhibitory effect of omeprazole on motility of H. pylori was tested in semi-solid medium. MIC of omeprazole micronized was 20 micro g/ml. Omeprazole could inhibit induced vacuolation by the water extract of H. pylori strains in Vero cells. It could also inhibit vacuolation induced by urease. Inhibition of vacuolation strains was assessed microscopically and by the neutral red method. It was also found that omeprazole inhibits the motility of H. pylori strains at concentrations lower than MIC. The results of this study suggest that omeprazole micronized could neutralize the vacuolation effect of H. pylori cytotoxin on Vero cells probably by targeting v-type ATPase. The bacterial motility was also inhibited by low concentrations of omeprazole. The results of this study considers omeprazole micronized as an effective drug which targets important virulence factors of H. pylori including vacuolating cytotoxin, urease, and motility