Responses to reactive oxygen intermediates and virulence of Salmonella typhimurium.
Salmonella typhimurium is an intracellular pathogen that can survive and replicate in macrophages. One of the host defense mechanisms that S. typhimurium encounters upon infection is superoxide produced by the phagocytes' NADPH-oxidase. Salmonella has evolved numerous ways of coping with superoxide in the extracellular environment. In addition, Salmonella has to defend itself against superoxide produced as a by-product of aerobic respiration. Over the last decade, research on bacterial mutants has led to the identification of Salmonella strains that differ from their parental strain in susceptibility to superoxide in vitro. However, the consequences of such mutations for bacterial virulence are highly variable, indicating that superoxide sensitivity per se is not a characteristic that renders Salmonella less virulent. By discussing various bacterial mutants classified according to their in vitro sensitivity to superoxide, we will exemplify the complex mechanisms that Salmonella has evolved to cope with superoxide stress.
Janssen
Riny
R
Department of Infectious Diseases, C5-P, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands. c.m.janssen@lumc.nl
van der Straaten
Tahar
T
van Diepen
Angela
A
van Dissel
Jaap T
JT
D000818:Animals; D006801:Humans; D009154:Mutation; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity*; D013481:Superoxides / Q000494:pharmacology; D014774:Virulence
D017382:Reactive Oxygen Species; D013481:Superoxides