CELL-ENVELOPE CHARACTERISTICS OF HELICOBACTER-PYLORI - THEIR ROLE IN ADHERENCE TO MUCOSAL SURFACES AND VIRULENCE

Helicobacter pylori colonises the gastric mucosa of humans and causes both antral gastritis and duodenal ulcer disease. Exactly how H. pylor i causes disease is not known but several pathogenic determinants have been proposed for the organism. These include adhesins, cytotoxins an d a range of different enzymes including urease, catalase and superoxi de dismutase. Surface molecules of H. pylori such as flagella, lipopol ysaccharide, the urease enzyme and outer membrane proteins are putativ e adhesin molecules. While phosphatidylethanolamine and the Lewis(b) b lood group antigen have been proposed as receptor molecules for the or ganism the exact mechanism by which H. pylori adheres to the gastric m ucosa has still to be identified. Characterisation of the adhesins of H. pylori could lead to the development of adhesin analogues for use i n the inhibition of colonisation and improved therapy for ulcer diseas e. In vivo studies with isogenic mutants which are incapable of adheri ng to the gastric mucosa would greatly clarify the significance of adh erence. Such mutants could possibly be useful as a vaccine against inf ection with wild-type organisms.