A 21 year old college female shows up at the student health clinic with complaints abdominal cramping and diarrhea of recent onset. There is no history of recent travel. A few days ago, she attended a sorority picnic hosted with one of the fraternities on campus.
Labs: Stool sample contains gram negative oval rods and PMN leukocytes, does not ferment lactose on MacConkey's agar. It grows better at 25 degrees Celsius than at 37 degrees Celsius.