Which bacterium is primarily responsible for Yersiniosis?

Yersiniosis is primarily caused by Yersinia enterocolitica, making it the correct answer. This bacterium is associated with gastrointestinal infections and can be transmitted through contaminated food, particularly undercooked pork, and unpasteurized milk. Infections with Yersinia enterocolitica can lead to symptoms such as diarrhea, fever, and abdominal pain, sometimes mimicking appendicitis.

While Yersinia pestis is another species within the Yersinia genus, it is primarily known for causing the plague and is not associated with yersiniosis. Corynebacterium diphtheriae is responsible for diphtheria, a respiratory illness, and does not have a role in causing yersiniosis. Brucella spp., which causes brucellosis, is a different genus that is not related to the symptoms or transmission associated with Yersinia enterocolitica. Thus, the role of Yersinia enterocolitica as the causative agent for yersiniosis is well-established in both clinical and epidemiological contexts.