A patient with chronic granulomatous disease would most likely have difficulty neutralizing which type of bacteria?

Chronic granulomatous disease (CGD) is a genetic disorder that affects the immune system, specifically the ability of phagocytes such as neutrophils to produce reactive oxygen species (ROS) during the process of phagocytosis. This impairment in the oxidative burst makes it difficult for the body to effectively kill certain types of bacteria.

Catalase-positive bacteria are particularly problematic for patients with CGD. These bacteria, which include species such as Staphylococcus and Aspergillus, have the enzyme catalase that breaks down hydrogen peroxide (H2O2) into water and oxygen. In individuals with a normal immune system, hydrogen peroxide acts as an important antimicrobial agent produced by phagocytes to kill ingested pathogens. However, in CGD patients, because their immune cells cannot generate sufficient ROS, they are dependent on hydrogen peroxide from the environment to help kill these bacteria. Since catalase-positive bacteria can neutralize hydrogen peroxide using their own catalase, the immune system of a CGD patient is left unable to effectively combat these infections, leading to an increased susceptibility to these organisms.

In contrast, catalase-negative bacteria do not have this enzymatic capability and are usually susceptible to hydrogen peroxide, allowing patients with CGD to manage infections from