Small, lactose negative colonies of Yersinia enterocolitica on Endo agar (1-2 mm in diameter). Cultivation 24 hours, 37°C.
Yersinia enterocolitica infection causes the disease yersiniosis which is a zoonotic disease occurring in humans as well as a wide array of animals such as cattle, deer, pigs, and birds.
Acute Y. enterocolitica infections usually lead to mild self-limiting enterocolitis or terminal ileitis in humans. Symptoms may include watery or bloody diarrhea and fever. After oral uptake yersiniae replicate in the terminal ileum and invade Peyer's patches.
From here yersiniae can disseminate further to mesenteric lymph nodes causing lymphadenopathy. Ths condition can be confused with appendicitis and is therefore called pseudoappendicitis.