An aerobic gram-positive rod known to cause bacteremia in hospitalized, patients who are immunocompromised is which organism?

• A. Bacillus anthracis
• B. Corynebacterium jeikeium
• C. Corynebacterium ulcerans
• D. Corynebacterium urealyticum

Answer: (B)

In this scenario, the infection is a hospital-acquired bloodstream infection in an immunocompromised patient, which points to a gram-positive rod that often behaves as a nosocomial pathogen associated with indwelling devices. Corynebacterium jeikeium fits this pattern: it is a gram-positive, non-spore-forming aerobic rod that is part of normal skin flora but can cause bacteremia in patients with weakened immune systems or who have catheters or prosthetic devices. These patients are especially at risk for bloodstream infections, and Corynebacterium jeikeium is known for being multidrug resistant, making vancomycin a common treatment choice.

Bacillus anthracis, while a gram-positive rod, causes anthrax with toxin-mediated disease and is not a typical cause of nosocomial bacteremia in hospitalized immunocompromised patients. Corynebacterium ulcerans can cause diphtheria-like illness and is less associated with bacteremia in this context. Corynebacterium urealyticum more commonly causes urinary tract infections and encrusting cystitis rather than bloodstream infection.