Yersinia enterocolitica is an infrequent cause of bacterial diarrheal infection, usually in children. Infection has been associated with ingestion of undercooked pork, dairy products, and tainted water. Infection can also be transmitted by the fecal " “oral route. Symptoms are fairly nonspecific: fever, abdominal pain, and diarrhea, which may be bloody. Abdominal pain in adults may mimic appendicitis. This test is a specialized stool culture for the detection of GI infection caused by Y. enterocolitica.
Use
Cold enrichment, holding stool suspended in buffered saline at 4 ‚ °C prior to subculture onto enteric media, may improve recovery in heavily contaminated specimens. Y. enterocolitica may be isolated using a selective medium, like MacConkey agar. Many laboratories use a more selective medium, like CIN agar (cefsulodin " “ingrasan " “novobiosin), to improve recovery. Y. enterocolitica isolation may be improved by culture incubation at 25 ‚ °C.
Turnaround time: Cultures are examined for 48 hours. Several days are required for isolation and identification of suspected isolates.
Interpretation
Expected results: No growth.
Limitations
The symptoms of yersiniosis are not specific, and this enteric pathogen may not be suspected unless specific risk factors or epidemiologic evidence suggests this infection. Isolates are sucrose positive, so isolates may be missed by laboratories using EMB agar for enteric cultures. (The EMB medium contains sucrose so isolates will look similar to normal enteric flora.)