Helicobacter Pylori Molecular Mimicry between Pathogen and Host Free Essay Example, 3750 words

Until 1991, medical microbiologists had been teaching that the stomach environment was too harsh to support microbes. This changed following the discovery of Helicobacter pylori, which opened an exciting new chapter in our understanding of bacterial life (Rabeneck and Ranshoff, 1991). Helicobacter pylorus not only grows and thrives in the stomach, but it may also be responsible for 90% of gastric and duodenal ulcers, though most infections are asymptomatic. Helicobacter pylori produce large amounts of urease, which converts urea into ammonia and carbon dioxide. Bacteria survive the stomach environment by being surrounded by ammonia molecules, which neutralize stomach acids. Many bacteria invade the mucin layer, but only H. pylori have the adhesins that bind to mucosal cells. These adhesins include Lewis blood group O antigens, phosphatidyl-ethanolamine, sialic acid, and laminin. H. pylori also produce cytotoxins that cause the symptoms of peptic ulcers. The cytotoxins produce vacuol es within the mucosal cells lining the stomach and small intestine. When the injected mucosal cells die, gastric acids and digestive enzymes cause the formation of ulcers. H. pylori isolated from patients with peptic ulcer disease and with gastric cancer contained a 38-kb fragment of DNA that was not present in asymptomatic carriers. We will write a custom essay sample on Helicobacter Pylori: Molecular Mimicry between Pathogen and Host or any topic specifically for you Only $17.96 $11.86/page