Salmonella detoxifying enzymes are sufficient to cope with the host oxidative burst

Authors

  • Laurent Aussel,

    1. Laboratoire de Chimie Bactérienne – Institut de Microbiologie de la Méditerranée – IFR 88, UPR 9043 du CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
    2. Aix-Marseille University, Marseille, France
    Search for more papers by this author
  • Weidong Zhao,

    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author
  • Magali Hébrard,

    1. Laboratoire de Chimie Bactérienne – Institut de Microbiologie de la Méditerranée – IFR 88, UPR 9043 du CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
    2. Aix-Marseille University, Marseille, France
    Search for more papers by this author
  • Aude-Agnès Guilhon,

    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author
  • Julie P. M. Viala,

    1. Laboratoire de Chimie Bactérienne – Institut de Microbiologie de la Méditerranée – IFR 88, UPR 9043 du CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
    2. Aix-Marseille University, Marseille, France
    Search for more papers by this author
  • Sandrine Henri,

    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author
  • Lionel Chasson,

    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author
  • Jean-Pierre Gorvel,

    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author
  • Frédéric Barras,

    Corresponding author
    1. Laboratoire de Chimie Bactérienne – Institut de Microbiologie de la Méditerranée – IFR 88, UPR 9043 du CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
    2. Aix-Marseille University, Marseille, France
    Search for more papers by this author
  • Stéphane Méresse

    Corresponding author
    1. Aix-Marseille University, Marseille, France
    2. Centre d'Immunologie de Marseille-Luminy, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9, France
    3. CNRS, UMR6102, Marseille, France
    4. INSERM, U631, Marseille, France
    Search for more papers by this author

E-mail barras@ifr88.cnrs-mrs.fr; Tel. (+33) 491 16 45 79; Fax (+33) 491 71 89 14;

E-mail meresse@ciml.univ-mrs.fr; Tel. (+33) 491 26 91 15; Fax (+33) 491 26 94 30.

Summary

The oxidative burst produced by the NADPH oxidase (Phox) is an essential weapon used by host cells to eradicate engulfed pathogens. In Salmonella typhimurium, oxidative stress resistance has been previously proposed to be mediated by the pathogenicity island 2 type III secretion system (T3SS-2), periplasmic superoxide dismutases and cytoplasmic catalases/peroxidases. Here, we fused an OxyR-dependent promoter to the gfp to build the ahpC-gfp transcriptional fusion. This reporter was used to monitor hydrogen peroxide levels as sensed by Salmonella during the course of an infection. We showed that the expression of this fusion was under the exclusive control of reactive oxygen species produced by the host. The ahpC-gfp expression was noticeably modified in the absence of bacterial periplasmic superoxide dismutases or cytoplasmic catalases/peroxidases. Surprisingly, inactivation of the T3SS-2 had no effect on the ahpC-gfp expression. All together, these results led to a model in which Salmonella resistance relies on its arsenal of detoxifying enzymes to cope with Phox-mediated oxidative stress.

Ancillary