Article révisé par les pairs
| Résumé : | Helicobacter pylori is associated with diverse pathologies of varying severity, such as chronic gastritis, peptic ulceration, MALT lymphoma and gastric adenocarcinoma. This broad diversity of outcomes is explained, at least in part, by the heterogeneity of the H. pylori quasispecies. Mosaicism, illustrated by the vacuolating cytotoxin gene (vacA) and non-conserved genes, as those belonging to the cag pathogenicity island, take part in the genetic diversity of the microorganism. In addition, non-proteinaceous elements such as the lipopolysaccharide, contribute also to the heterogeneity of H. pylori. However, all clinical isolates are motile and display a strong urease activity. These common features are indispensable for the persistent colonization of the gastric mucosa. Both variable and conserved virulence factors are reviewed here, from the angle of genetics and molecular biology. The molecular analyses, culminating with the recent sequencing of the H. pylori genome, afford answers to but also new questions over the H. pylori challenge. |
