Review Question - QID 109837

A 46-year-old man presents to his primary care provider for an ulcerating skin lesion on his leg for the past week. He says that the week prior he slipped while hiking and scraped his left leg. Over the course of the next week, he noticed redness and swelling of the scraped area and the development of a nodule that eventually ulcerated. On exam, his temperature is 99.5°F (37.5°C), blood pressure is 136/92 mmHg, pulse is 88/min, and respirations are 12/min. Over his left lateral leg is an erythematous patch with a 2-cm nodule with central ulceration. Staining of a sample from the nodule demonstrates gram-positive organisms that are also weakly acid-fast. Morphologically, the organism appears as branching filaments. Which of the following should be used to treat this infection?