A young man has recurrent abscesses caused by Staphylococcus aureus, Serratia marcescens, and invasive Aspergillus. The nitroblue tetrazolium dye reduction test is abnormal. Which of the following organisms would he be expected to handle normally?

• A Staphylococcus aureus
• B Serratia marcescens
• C Aspergillus fumigatus
• D Streptococcus pneumoniae ✓

Explanation

Chronic granulomatous disease results from defective phagocyte NADPH oxidase, so the respiratory burst cannot generate superoxide. Catalase-positive organisms such as S aureus, Serratia, Burkholderia, Nocardia, and Aspergillus destroy their own hydrogen peroxide and survive inside the phagosome. Catalase-negative organisms like Streptococcus pneumoniae accumulate endogenous hydrogen peroxide, which the phagocyte can use via myeloperoxidase to kill them, so pneumococcal infections are not characteristic of CGD.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.