Question

A 52 year old man with dyspepsia is found to have a duodenal ulcer. A CLO test is taken and is positive. Which statement relating to the likely causative organism is false?

a. it is a gram negative organism
b. it preferentially colonises gastric type mucosa
c. it may occupy areas of ectopic gastric metaplasia
d. in patients who are colonised there is commonly evidence of fundal gastritis on endoscopy
e. it produces a powerful urease that forms the basis of the Closure test

Answer 1

The false statement about the causative organism of the duodenal ulcer, Helicobacter pylori, is that in patients who are colonised, there is common evidence of fundal gastritis on endoscopy. H. pylori more often affects the antrum rather than the fundus of the stomach.

Step-by-step explanation:

The CLO test is used to diagnose infection with Helicobacter pylori, a gram-negative bacterium that is a common cause of peptic ulcers. The statement that is false regarding the likely causative organism is d. "in patients who are colonized there is common evidence of fundal gastritis on endoscopy." Although H. pylori infection can lead to chronic gastritis, it predominantly affects the antrum of the stomach rather than the fundus. The organism:

• Is indeed a gram-negative organism (a).
• Preferentially colonizes gastric-type mucosa (b).
• May occupy areas of ectopic gastric metaplasia (c).
• Produces a powerful urease that neutralizes stomach acid, allowing it to survive in the stomach's acidic environment, which is also the basis for the CLO test (e).

Therefore, the false statement in context is related to the typical location of gastritis caused by H. pylori, which is not commonly the fundus but rather the lower sections of the stomach.