Get access

Interaction of enteroaggregative Escherichia coli with salad leaves

Authors

  • Cedric N. Berger,

    Corresponding author
    1. Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.
    Search for more papers by this author
    • These authors are equal contributors.

  • Robert K. Shaw,

    1. Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.
    2. School of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, UK.
    Search for more papers by this author
    • These authors are equal contributors.

  • Fernando Ruiz-Perez,

    1. Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA.
    Search for more papers by this author
  • James P. Nataro,

    1. Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA.
    Search for more papers by this author
  • Ian R. Henderson,

    1. School of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, UK.
    Search for more papers by this author
  • Mark J. Pallen,

    1. School of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, UK.
    Search for more papers by this author
  • Gad Frankel

    1. Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.
    Search for more papers by this author

*E-mail c.berger@imperial.ac.uk; Tel. (+44) 20 75945253; Fax (+44) 20 75943069.

Summary

Enteroaggregative Escherichia coli (EAEC) are important human pathogens. However, their environmental reservoir is unknown. As fresh salad leaves are increasingly recognized as an important environmental vector for human pathogens, we investigated leaf attachment capability of EAEC strains. We found that binding of clinical EAEC isolates to leaves from Eruca vesicaria (commonly known as rocket or arugula) can be divided into high, moderate and low adherent phenotypes. Using the prototype EAEC strain 042 to investigate the underlining mechanisms involved in leaf attachment, we found small attached bacterial aggregates over the entire leaf surface and dense bacterial attachment to the guard cell of the stomata. An aaf 042 mutant lost the ability to bind the epidermis while retaining stomatal adherence. In contrast, a fliC 042 mutant retained the ability to bind the epidermis but lost stomatal tropism. These results show that multiple adherence factors are involved in the interaction of EAEC with leaves, that EAEC uses similar colonization factors to bind mucosal and leaf surfaces and that fresh produce might be an important reservoir of EAEC strains.

Ancillary