Which microorganism is associated with peptic ulcer formation?

Helicobacter pylori is a key bacterium associated with peptic ulcer formation. It is a gram-negative, spiral-shaped bacterium that colonizes the stomach and is known to disrupt the protective mucous layer of the gastric epithelium. This disruption can lead to inflammation (chronic gastritis) and is a significant factor in the development of both gastric and duodenal ulcers. The ability of H. pylori to survive in the acidic environment of the stomach and its production of urease, which neutralizes stomach acid, are critical to its pathogenicity. Furthermore, infection with H. pylori is linked to an increased risk of gastric cancer.

The other microorganisms listed are not typically associated with peptic ulcers. Vibrio cholerae is primarily known for causing cholera and gastrointestinal distress. Clostridium tetani is known for causing tetanus, a serious disease that affects the nervous system. Campylobacter spp., while it can cause gastrointestinal infections, is more related to foodborne illness than directly to peptic ulcers. Thus, Helicobacter pylori stands out as the established pathogen connected to the development of peptic ulcers.