Microbial Pathogens: Helicobacter pylori and Hepatitis Viruses

Which enzyme produced by Helicobacter pylori is essential for its survival in the acidic environment of the stomach, and how is this enzyme detected in a clinical diagnostic test?

A patient presents with chronic gastritis and is found to have a spiral-shaped, Gram-negative bacterium with multiple polar flagella in a gastric biopsy. Which of the following is the most likely long-term complication if the infection is left untreated?

Which blood type is associated with a significantly increased risk of peptic ulcers due to Helicobacter pylori infection?