Acknowledgments
We would like to express our gratitude to Patrick Trieu-Cuot for his constant support and useful comments on this work. We thank Adeline Mallet (Imagopole, Ultrastructural Microscopy Platform) for providing the picture used for Fig. 1. We thank Mariana Martins, Anne-Marie Di Guilmi, Michel-Yves Mistou and Chantal Le Bouguenec for critical reading of the manuscript. S. Dramsi is funded by the Institut Pasteur and the French National Research Agency (ANR Blanc Glyco-Path).