Rust-colored sputum is a classic clue for pneumonia caused by which organism?

Rust-colored sputum is a classic clue for pneumonia caused by which organism?

• A. Corynebacterium jeikeium
• B. Staphylococcus aureus
• C. Streptococcus pneumoniae
• D. Streptococcus pyogenes

Answer: (C)

Rust-colored sputum points to pneumococcal pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia in adults and is classically associated with this sputum color. The rust tint comes from blood-tinged material in the airways as the inflammatory exudate damages alveolar walls during infection. S. pneumoniae is a Gram-positive, lancet-shaped diplococcus that is alpha-hemolytic on blood agar and is optochin sensitive and bile soluble, giving lab clues to its identity. While other bacteria can cause pneumonia, this particular sputum color is the hallmark association with Streptococcus pneumoniae.

Rust-colored sputum points to pneumococcal pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia in adults and is classically associated with this sputum color. The rust tint comes from blood-tinged material in the airways as the inflammatory exudate damages alveolar walls during infection. S. pneumoniae is a Gram-positive, lancet-shaped diplococcus that is alpha-hemolytic on blood agar and is optochin sensitive and bile soluble, giving lab clues to its identity. While other bacteria can cause pneumonia, this particular sputum color is the hallmark association with Streptococcus pneumoniae.