A 75-year-old man with neurogenic bladder has an indwelling long-term

urinary catheter. Due to ongoing health problems the patient is frequently

hospitalized. For the last two days, he has had fever and rigors, and blockage

of the catheter. Blood culture reveals the presence of Gram-negative bacilli

which are oxidase-positive and non-glucose fermenters on MacConkey agar.

Which bacterium is the most likely cause of the catheter–related

infection?