Describe Helicobacter pylori. What major enzymes does this organism produce to enable it to survive in the host? How common is an H. pylori infection? What is the age and social distribution of people infected by this organism? Describe in detail the likely pathogenic process. Which gastrointestinal disorders are associated with H. pylori infection? How is H. pylori infection diagnosed? In addition to drug treatment, what lifestyle advice should be given to patients with peptic ulcers?