Question

"Six days after an uncomplicated left nephrectomy, a 42-year-old man complains of moderate abdominal pain and diarrhea. He is stooling approximately 6 times a day with profuse watery diarrhea. The patient also experiences painful cramps during these episodes. In other medical history, the patient has a history of hypertension and elevated cholesterol. His medications include metoprolol (Lopressor) and simvastatin (Zocor). He denies any recent cardiopulmonary history and any history of chronic gastrointestinal disorders. His chart indicates that he received a 2-day regimen of cefazolin (Ancef) for perioperative skin prophylaxis. His temperature is 38.3°C (101.0°F). Stool is positive for fecal leukocytes and occult blood. The diagnosis is established with additional studies and he is given treatment. Unfortunately he fails to respond to therapy and requires surgery. An image of a segment of his colon is shown.

Which of the following is the most likely pathogen?" A. Bacillus cereus
B. Clostridium difficile
C. Escherichia coli 0157:H7
D. Shigella
E. Yersinia enterocolitica

Answer 1

The most likely pathogen in this case is Clostridium difficile, which is commonly associated with antibiotic use and can cause diarrhea and other gastrointestinal symptoms.

Step-by-step explanation:

The most likely pathogen in this case is Clostridium difficile (Option B). Clostridium difficile is a bacterium that can cause diarrhea and other gastrointestinal symptoms. It is commonly associated with antibiotic use, as the antibiotics can disrupt the normal gut flora and allow Clostridium difficile to overgrow.

In the case described, the patient had received antibiotics (cefazolin) for perioperative prophylaxis, which can increase the risk of Clostridium difficile infection. The symptoms of profuse watery diarrhea, abdominal pain, and positive stool for fecal leukocytes and occult blood are consistent with Clostridium difficile infection.

Other options such as Bacillus cereus, Escherichia coli 0157:H7, Shigella, and Yersinia enterocolitica are less likely in this case based on the clinical presentation and the patient's medical history.