A 48-Year-Old Man Comes to the Emergency Department Due to Pain

question 403

Multiple Choice

A 48-year-old man comes to the emergency department due to pain in his right foot and leg.  Yesterday, the patient sailed a friend's boat on the ocean and sustained a small cut to his right foot while jumping onto the dock.  He stopped the bleeding using direct pressure and washed the wound with antiseptic.  Last night, he awoke with throbbing pain in the right foot.  The patient took ibuprofen, but the pain progressively worsened.  A few hours later, he developed fever with rigors.  The patient was recently diagnosed with hereditary hemochromatosis after laboratory studies showed abnormal liver aminotransferases and elevated transferrin saturation.  He has not received treatment and has no other medical problems.  He does not use tobacco, alcohol, or illicit drugs.  Temperature is 39.4 C (103 F) , blood pressure is 100/60 mm Hg, and pulse is 120/min.  The patient is in moderate distress.  Physical examination shows a 1.5-cm laceration on the dorsum of the right foot with extensive surrounding edema, erythema, and several dark-colored bullae.  There is streaking erythema extending up the proximal right thigh.  Leukocyte count is 21,000/mm³.  Which of the following is the most likely causative organism of this patient's current condition?

• A)Pasteurella multocida
• B)Pseudomonas aeruginosa
• C)Staphylococcus aureus
• D)Streptococcus pyogenes
• E)Vibrio vulnificus