title: Susceptibility of micro-organisms to active oxygen species: sensitivity to the xanthine-oxidase-mediated antimicrobial system.
abstract: Xanthine oxidase with acetaldehyde as substrate (the XOA system) generated superoxide anion and hydrogen peroxide, but this system had only weak bactericidal activity. Addition of Fe2+ and EDTA to the XOA system (XOA-Fe-EDTA system) increased bactericidal activity against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Salmonella typhimurium, although both Mycobacterium tuberculosis and Candida albicans remained highly resistant. Catalase (H2O2 scavenger) and mannitol (.OH scavenger) almost completely inhibited the bactericidal activity of the XOA-Fe-EDTA system whereas SOD (O2- scavenger) was less inhibitory. Azide (1O2 scavenger) caused no such inhibition. The results suggest the possible role of .OH, H2O2 and O2- in the XOA-Fe-EDTA-mediated antimicrobial system, as effector molecules. There was no correlation between resistance of a given bacterium to active oxygen and the level of endogenous active oxygen-scavengers.
mesh_terms: D002176:Candida albicans / Q000187:drug effects; D002374:Catalase / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D005296:Ferrous Compounds / Q000494:pharmacology*; D007502:Iron Chelating Agents / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013482:Superoxide Dismutase / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000494:pharmacology*
chemical_list: D005296:Ferrous Compounds; D007502:Iron Chelating Agents; D004492:Edetic Acid; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase