After a visit to Chicago over Christmas, a couple returns to St. Louis with nausea, diarrhea, and cramping in the lower right quadrant of their abdomens. They admitted to indulging in a family favorite of chitterlings over the holidays. The routine stool culture of both individuals provided the same results:
BAP: all colonies present are oxidase negative and no beta-hemolytic colonies observed
MAC: lactose fermenters and oxidase negative, non-lactose fermenters HE: yellow colonies
PEA: no suspicious colonies
Campy blood agar: no growth
Based on the patient history, the original orders also requested the stool specimens be cultured for an additional enteric pathogen. The processing technician noted the request and added one
Additional agar plate to the routine stool culture media. The additional agar demonstrates the potential enteric pathogen as _________ colonies.

Question

Quizplus · Accepted Answer

The symptoms and the consumption of chitterlings suggest an infection with Yersinia enterocolitica, which typically produces red-centered colonies with clear edges on CIN (Cefsulodin-Irgasan-Novobiocin) agar, the likely additional agar plate used for culturing this pathogen.

After a Visit to Chicago Over Christmas, a Couple Returns