Question

Catalase (-) organism that shows (+) capsular swelling on a Quellung test?

Accepted Answer

S.pneumoniae → anti-capsular Ab elicits a “swelling” or “halo” surrounding the organism → rules out ∆sis of tuberculosis as no other pathogens that cause Community-Acquired pneumonia (CAP) produce this result

Front	Catalase (-) organism that shows (+) capsular swelling on a Quellung test?
Back	S.pneumoniae → anti-capsular Ab elicits a “swelling” or “halo” surrounding the organism → rules out ∆sis of tuberculosis as no other pathogens that cause Community-Acquired pneumonia (CAP) produce this result

Organism Catalase Shows Capsular Swelling Quellung Test S.Pneumoniae