Which statement about Campylobacter jejuni is true?

• A. Catalase negative
• B. Isolated best at 24°C
• C. Commonly found in ocean water
• D. A leading cause of bacterial diarrhea worldwide

Answer: (D)

Campylobacter jejuni is a leading cause of bacterial diarrhea worldwide. It’s a curved, Gram‑negative, oxidase‑ and catalase‑positive bacterium that prefers microaerophilic conditions and grows best at about 42°C, reflecting its association with poultry. This means statements claiming it is catalase negative or that it is best isolated at 24°C are not correct, since its enzymes are active and its optimal recovery temperature is higher than room temperature. It isn’t primarily an ocean‑water organism; its main reservoirs are animals and contaminated food or water. The global impact on diarrheal illness makes the true statement that Campylobacter jejuni is a leading cause of bacterial diarrhea worldwide.