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Microbiology 11

A 28-year-old woman presents to the emergency department complaining of diarrhea with mild abdominal pain for the past two days. She describes the diarrhea as being watery and non-bloody, and also notes that she has had a decreased appetite since around the time the symptoms began. She reports that she recently returned from a trip to Thailand where she sampled a significant amount of local street food. Her vital signs are temperature of 98.7°F (37°C), blood pressure 122/62 mmHg, heart rate 64 beats/minute, and respirations 18/minute. On physical examination, she appears healthy. Abdominal examination is without guarding or focal tenderness to palpation. Gram-staining of the stool reveals gram negative rods.

Which of the following media and findings would correctly identify this organism?

  • A) Eosin-Methylene Blue (EMB) agar; black colonies
  • B) Hektoen agar; green colonies
  • C) MacConkey agar; extremely mucoid colonies
  • D) MacConkey agar; pink colonies


Daniel Pak


Dr. Ted O'Connell

Last updated

Feb 11, 2024


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