Editing Catalase (section)

=== Bacterial virulence ===
[[Neutrophil]]s and other [[phagocyte]]s use peroxide to kill bacteria. The enzyme [[NADPH oxidase]] generates [[superoxide]] within the [[phagosome]], which is converted via hydrogen peroxide to other oxidising substances like [[hypochlorous acid]] which kill [[phagocytosed]] pathogens.<ref>{{cite journal | vauthors = Winterbourn CC, Kettle AJ, Hampton MB | title = Reactive Oxygen Species and Neutrophil Function | journal = Annual Review of Biochemistry | volume = 85 | issue = 1 | pages = 765–792 | date = June 2016 | pmid = 27050287 | doi = 10.1146/annurev-biochem-060815-014442 }}</ref> In individuals with [[chronic granulomatous disease]] (CGD), phagocytic peroxide production is impaired due to a defective NADPH oxidase system. Normal cellular metabolism will still produce a small amount of peroxide and this peroxide can be used to produce hypochlorous acid to eradicate the bacterial infection. However, if individuals with CGD are infected with catalase-positive bacteria, the bacterial catalase can destroy the excess peroxide before it can be used to produce other oxidising substances. In these individuals the pathogen survives and becomes a chronic infection. This chronic infection is typically surrounded by macrophages in an attempt to isolate the infection. This wall of macrophages surrounding a pathogen is called a [[granuloma]]. Many bacteria are catalase positive, but some are better catalase-producers than others. Some catalase-positive bacteria and fungi include: ''[[Nocardia]], [[Pseudomonas]], [[Listeria]], [[Aspergillus]], [[Candida albicans|Candida]], [[Escherichia coli|E. coli]], [[Staphylococcus]], [[Serratia]], [[Burkholderia cepacia complex|B. cepacia]]'' and ''[[Helicobacter pylori|H. pylori]]''.<ref>{{Cite book|title=First aid for the USMLE step 1 2017: a student-to-student guide |isbn=978-1-259-83762-3 |edition=27th |location=New York |publisher=McGraw-Hill Education |oclc=986222844| vauthors = Le T, Bhushan V, Sochat M, Kallianos K, Chavda Y, Zureick AH |date = 2017-01-06}}</ref>