Added a tag for a question on NBME form 11 because this card directly relates to the answer of the question, see below:
A 72-year-old woman with a 30-year history of type 2 diabetes mellitus comes to the physician because of pain and swelling of her left foot since a blister on the bottom of her left foot broke 2 weeks ago. Her temperature is 37.2°C (99°F). Examination shows swelling and erythema of the left distal leg, ankle, and foot; there is a 2-cm ulcer at the base of the heel with an overlying black eschar. Peripheral pulses are decreased bilaterally. Capillary refill time is greater than 3 seconds. The ulcer is debrided, and a sterile probe is inserted until the base touches bone. Which of the following is the most likely cause of these findings?
Answer: Mixed aerobic and anaerobic organisms