In CGD, the bacterial killing mechanisms that depend on the phagocyte oxidase system are inoperative, but the nonoxidative killing mechanisms are still intact. Therefore, patients with CGD are not troubled by the broad range of microbes that a neutropenic patient would be susceptible to. Instead, CGD patients get infections a restricted range of microorganisms, which are only susceptible to the bactericidal mechanisms initiated by NADPH oxidase activation. The spectrum of organisms that causes infections in CGD include S. aureus, Gram-negative bacteria (Burkholderia cepacea, Salmonella, Serratia), and fungi (Aspergillus spp). Characteristic sites of infection include subcutaneous tissue, lymph nodes, lungs, and liver. Oral and perioral ulceration are common.