A 35-year-old auto salesman arrives at the clinic with a rash that emerged 48 hours after using a hot tub. The day after the rash appeared, he got chills and a fever. Even though he had been taking trimethoprim/sulfamethoxazole orally for two days, the rash developed and the fever remained. Normal vital signs and his temperature is 39°C. His examination showed several erythematous nodules on the upper trunk and a few on his abdomen that were one to three millimeters in size and not fluctuating as is shown in the picture below. However, there were two or three superficial, tender, painful, erythematous nodules in the bilateral axilla that were fluctuant in size and ranged from 0.5 to 1 cm. Each nodule generated a modest quantity of viscous, purulent exudate after incision and drainage. Which of the following infections is the most likely diagnosis,