The <i>Vibrio cholerae</i> Type VI Secretion System Can Modulate Host Intestinal Mechanics to Displace Commensal Gut Bacteria

ORAL

Abstract

Host-associated microbiota help defend against bacterial pathogens; the physical and chemical mechanisms by which pathogens overcome this defense, however, remain largely unknown. We applied live imaging to larval zebrafish to study how the human pathogen Vibrio cholerae invades the intestine. The gut microbiota of fish mono-colonized by commensal strain Aeromonas veronii was displaced by V. cholerae expressing its Type VI Secretion System (T6SS), a syringe-like apparatus that deploys toxins into target cells. Surprisingly, displacement was independent of T6SS-mediated killing of Aeromonas, driven instead by T6SS-induced enhancement of zebrafish intestinal movements that led to expulsion of the resident commensal by the host. Deleting an actin crosslinking domain from the T6SS apparatus returned intestinal motility to normal and thwarted expulsion, without weakening V. cholerae's ability to kill Aeromonas in vitro. Our finding that bacteria can manipulate host physiology to influence inter-microbial competition has implications for both pathogenesis and microbiome engineering.

*Support comes from the National Science Foundation; National Institutes of Health; the Research Corporation for Science Advancement; and the Kavli, Gordon and Betty Moore, and Simons Foundations.

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Presenters

  • Savannah Logan

    • Institute of Molecular Biology, Materials Science Institute, and Department of Physics, University of Oregon

Authors

  • Savannah Logan

    • Institute of Molecular Biology, Materials Science Institute, and Department of Physics, University of Oregon

  • Jacob Thomas

    • School of Biological Sciences, Georgia Institute of Technology
    • Georgia Inst of Tech

  • Jinyuan Yan

    • Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center

  • Ryan Baker

    • Institute of Molecular Biology, Materials Science Institute, and Department of Physics, University of Oregon

  • Drew Shields

    • Institute of Molecular Biology, Materials Science Institute, and Department of Physics, University of Oregon

  • Joao Xavier

    • Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center

  • Brian Hammer

    • School of Biological Sciences, Georgia Institute of Technology
    • Georgia Inst of Tech

  • Raghuveer Parthasarathy

    • Institute of Molecular Biology, Materials Science Institute, and Department of Physics, University of Oregon
    • Department of Physics, University of Oregon
    • University of Oregon