A group of organisms that produce catalase, an enzyme that degrades hydrogen peroxide into water and oxygen before neutrophils can convert it via myeloperoxidase into microbicidal products. Cause recurrent infections in patients with chronic granulomatous disease. Species include Nocardia, Pseudomonas, Listeria, Aspergillus, Candida, E. coli, Staphylococcus, Serratia, B. cepacia, and H. pylori.