Which of the following statements regarding Helicobacter pylori is not true?

• A. It is associated with an increased risk of gastric carcinoma.
• B. It is the cause of most cases of acute food poisoning in the United States.
• C. It is a major cause of peptic ulcers in the United States.
• D. It is positive for urease.

Answer: (B)

H. pylori is a urease-positive bacterium that colonizes the stomach and uses urease to convert urea into ammonia, helping it survive the acidic environment. This infection drives chronic gastritis and is a major cause of peptic ulcers; it also raises the risk for gastric cancer and MALT lymphoma. It does not cause most cases of acute food poisoning in the United States—those are typically due to preformed toxins or other pathogens such as Staphylococcus aureus, Salmonella, Campylobacter, or viral agents. So the statement that it is the cause of most acute food poisoning is not true, while its links to ulcers, cancer risk, and urease activity are correct.