Why is Yersinia enterocolitica often mistaken for appendicitis in children, and what growth characteristic aids detection?

• A. Causes gallbladder infection; grows in high salt
• B. Mimics appendicitis; grows only in anaerobic conditions
• C. Causes mesenteric adenitis mimicking appendicitis; grows well at cold temperatures (cold enrichment)
• D. Causes appendicitis-like diarrhea; grows best at body temperature

Answer: (A)

Yersinia enterocolitica often causes mesenteric adenitis, an inflammation of the lymph nodes in the mesentery near the ileocecal area, which can mimic appendicitis in children. This leads to right‑lower‑quadrant pain and similar clinical findings, so the infection is frequently mistaken for true appendicitis.

A key growth characteristic that aids detection is its ability to grow at cold temperatures. Yersinia is psychrotrophic, meaning it can multiply at refrigeration temperatures (around 4°C). In the lab, cold enrichment helps isolate it from stool or other samples: specimens are kept at 4°C for a period to suppress competing flora, then cultured to identify Yersinia. This cold‑temperature growth distinction is the practical diagnostic clue that improves detection in suspected cases.