What exists beyond cagA and vacA? Helicobacter pylori genes in gastric diseases

Abstract

The Helicobacter pylori (H. pylori) infection is present in more than half the world’s population and it has been associated with several gastric disorders, as gastritis, peptic ulceration and gastric adenocarcinoma. The clinical outcome of this infection depends on host and bacterium factors where H. pylori virulence genes seem to play a relevant role. Until now, cagA and vacA genes were studied and established in the literature as determining factors in gastric pathogenesis. However, there are percentages of gastric cancer cases that are cagA-negative. Several other virulence genes have been searched but these genes still remain in the shadow of cagA and vacA. Thus, this review aimed to bring up which genes have been suggested as potentially relevant virulence factors for H. pylori associated gastrointestinal diseases. We focused on the cagpathogenicity island, genes with adherence and motility functions and iceA based on its relevance shown in several studies in the literature.