Image of the Week: A purple urine bag

An 80-year-old woman with a history of diabetes and chronic constipation presents to the emergency department with a urine bag containing purple discoloration of urine. She is currently bedridden and uses an indwelling catheter. On examination, she is hypotensive and confused. Blood cultures are positive for Proteus vulgaris. Based on this patient’s presentation, which of the following antibiotics should be commenced? Learn more about this case, take the quiz, and join the conversation on Figure 1.