Which organism is classically associated with currant jelly sputum in pneumonia due to its thick capsule?

Which organism is classically associated with currant jelly sputum in pneumonia due to its thick capsule?

• A. Haemophilus influenzae
• B. Klebsiella pneumoniae
• C. Streptococcus pneumoniae
• D. Mycobacterium tuberculosis

Answer: (B)

Currant jelly sputum in pneumonia is most characteristic of Klebsiella pneumoniae because its thick, polysaccharide capsule makes the organism highly mucoid and resistant to phagocytosis. This capsule drives a very viscous, mucus-rich sputum that clinicians describe as currant jelly. Klebsiella commonly causes lobar pneumonia in individuals with risk factors like alcohol use or aspiration, and the capsule also contributes to the formation of glassy, mucoid colonies on culture. Other pneumonia pathogens can cause different sputum appearances (for example, rust-colored sputum with Streptococcus pneumoniae), but the distinctly thick, jelly-like sputum is classically linked to Klebsiella due to its capsule.

Currant jelly sputum in pneumonia is most characteristic of Klebsiella pneumoniae because its thick, polysaccharide capsule makes the organism highly mucoid and resistant to phagocytosis. This capsule drives a very viscous, mucus-rich sputum that clinicians describe as currant jelly. Klebsiella commonly causes lobar pneumonia in individuals with risk factors like alcohol use or aspiration, and the capsule also contributes to the formation of glassy, mucoid colonies on culture. Other pneumonia pathogens can cause different sputum appearances (for example, rust-colored sputum with Streptococcus pneumoniae), but the distinctly thick, jelly-like sputum is classically linked to Klebsiella due to its capsule.