Perverting cell-to-cell communication in streptococci

Bacteria have developed cell-to-cell communication systems to exchange information in order to coordinate a population response toward various stimuli. For instance, the ComR-ComS system is broadly present in streptococci and deeply studied in Pr. Pascal Hols´ lab and its postdoctoral researcher, Laura Ledesma-García. This sensor-pheromone duo is crucial for the adaptation and survival of bacteria as it activates the acquisition of free DNA available in the environment to reshape their genetic material. In addition, this system triggers the production of antimicrobial compounds to kill competitors present in the same niche. Throughout streptococci, the ComRS system has evolved differentially and, in many cases, no cross-communication between closely-related species was observed. In a study published in PNAS, the LIBST team and their collaborators (Pr. S. Nessler, University Paris-Sarclay) dissected the molecular determinants of pheromone selectivity and claimed the coevolution between communication molecules and their sensors. This research showcased how we can modulate the cross-talk capacity of those communication systems, making them responsive to different flavours of pheromones. Overall, this study paves the way to novel biotechnological applications, including the biocontrol of pathogens with designed biosensors able to detect pathogen pheromones and mobilize pathogen-killing molecules.

Molecular dissection of pheromone selectivity in the competence signaling system ComRS of streptococci., Laura Ledesma-Garcia, Jordhan Thuillier, Armando Guzman-Espinola, Imke Ensinck, Inès Li de la Sierra-Gallay, Noureddine Lazar, Magali Aumont-Nicaise, Johann Mignolet, Patrice Soumillion, Sylvie Nessler, and Pascal Hols, PNAS, published March 20, 2020, doi: 10.1073/pnas.1916085117.