Review Question - QID 202975

A 53-year-old man with type 2 diabetes mellitus presents to the emergency department complaining of the worst pain he has ever experienced in his right leg. He states that two days ago he cut his calf while working on the lawn. This morning he noticed a slight discoloration of his right calf. He says that although his leg does not look that bad, the pain is excruciating. Vital signs are as follows: T 102.5 F, HR 102 bpm, and BP 124/82. Physical exam reveals a slightly erythematous and swollen distal right calf that is extremely tender to palpation. A photo of the leg is shown in Figure A. What is the most common causative agent for this condition?