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Regulation of biofilm formation in Salmonella enterica serovar Typhimurium

    Roger Simm

    *Authors for correspondence:

    E-mail Address: ute.romling@ki.se

    ;

    E-mail Address: roger.simm@rr-research.no

    Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Montebello, Oslo, Norway

    Center for Cancer Biomedicine, Oslo University Hospital, Oslo, Norway

    ,
    Irfan Ahmad

    Department of Microbiology, Tumor & Cell Biology, Karolinska Institutet, Stockholm, Sweden

    ,
    Mikael Rhen

    Department of Microbiology, Tumor & Cell Biology, Karolinska Institutet, Stockholm, Sweden

    ,
    Soazig Le Guyon

    Department of Microbiology, Tumor & Cell Biology, Karolinska Institutet, Stockholm, Sweden

    &
    Ute Römling

    *Authors for correspondence:

    E-mail Address: ute.romling@ki.se

    ;

    E-mail Address: roger.simm@rr-research.no

    Department of Microbiology, Tumor & Cell Biology, Karolinska Institutet, Stockholm, Sweden

    Published Online:https://doi.org/10.2217/fmb.14.88

    ABSTRACT 

    In animals, plants and the environment, Salmonella enterica serovar Typhimurium forms the red dry and rough (rdar) biofilm characterized by extracellular matrix components curli and cellulose. With complex expression control by at least ten transcription factors, the bistably expressed orphan response regulator CsgD directs rdar morphotype development. CsgD expression is an integral part of the Hfq regulon and the complex cyclic diguanosine monophosphate signaling network partially controlled by the global RNA-binding protein CsrA. Cell wall turnover and the periplasmic redox status regulate csgD expression on a post-transcriptional level by unknown mechanisms. Furthermore, phosphorylation of CsgD is a potential inactivation and degradation signal in biofilm dissolution. Including complex incoherent feed-forward loops, regulation of biofilm formation versus motility and virulence is of recognized complexity.

    Papers of special note have been highlighted as: • of interest

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