Genes de virulência em Helicobacter pylori: componentes estruturais e métodos de detecção

Abstract

Helicobacter pylori is a Gram-negative bacterium that colonizes the human gastric mucosa, has been associated with gastrites, ulcers and is an important risk factor for the development of gastric cancer. Infection by the microorganism depends not only on environmental factors, but also on genetic factors of the host and bacteria. Thus, virulence factors produced by H. pylori have been the subject of several scientific studies, such as the cagA gene, which codes for an associated cytotoxin A and is involved with an increase in the inflammatory process; the vacA gene encoding a vacuolating cytotoxin; the babA gene encoding a bacterial adhesion protein that binds to the Lewis-b antigen, and the dupA, sabA and oipA genes that appear to be involved in the development of duodenal ulcers and adhesion of the bacterium to the gastric epithelium. Thus, the present work had as objective to analyze and describe the virulence factors of H. pylori, as well as to report the different methods of identification of virulence genes. This is a bibliographical review, where the data collection was carried out through scientific articles originating from the indexed databases. The results demonstrate the association of bacterial virulence genes with several gastric pathologies, however, the study should be extended with the elaboration of meta-analysis studies, as well as molecular analysis studies to evaluate the frequency of these virulence genes in several populations and associates them with the different clinical forms found in dyspeptic patients.