1 The Centre for Bacterial Cell Biology, The Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Baddiley-Clark Building, Newcastle upon Tyne, NE2 4AX, UK. katarzyna.mickiewicz@ncl.ac.uk.
2 The Centre for Bacterial Cell Biology, The Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Baddiley-Clark Building, Newcastle upon Tyne, NE2 4AX, UK.
3 Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
4 The Institute of Cellular Medicine, Newcastle University, 4th Floor, William Leech Building, Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
5 The Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
6 The Centre for Bacterial Cell Biology, The Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Baddiley-Clark Building, Newcastle upon Tyne, NE2 4AX, UK. jeff.errington@ncl.ac.uk.