In which condition would you expect increased susceptibility to infections by catalase-positive organisms?

Increased susceptibility to infections by catalase-positive organisms is primarily associated with Chronic Granulomatous Disease (CGD). This condition stems from a genetic defect that affects the phagocytes’ ability to produce reactive oxygen species (ROS) through the NADPH oxidase complex. These reactive species are critical for the destruction of various pathogens after they are engulfed by phagocytes such as neutrophils and macrophages.

In CGD, although phagocytes can engulf these pathogens, they cannot effectively kill certain types of bacteria and fungi, particularly those that are catalase-positive, such as Staphylococcus species and Aspergillus species. These organisms can neutralize hydrogen peroxide, which would typically be lethal to catalase-negative bacteria, allowing them to survive and cause infections, leading to recurrent and severe infections.

Other conditions listed do not directly predispose individuals to infections with catalase-positive organisms in the same manner. Xeroderma Pigmentosa is primarily characterized by sensitivity to ultraviolet light due to repair defects in DNA, while Hemophilia relates to bleeding disorders and does not impact the immune response. Sickle Cell Anemia is associated with encapsulated organisms due to functional asplenia but does not specifically elevate susceptibility to catalase-positive bacteria. Thus