Rousing Persisters through Ribosome Resuscitation and Rescue
Persistence, the dormant, stress-tolerant state formed primarily through the cessation of protein synthesis after antibiotic and nutrient stress, is arguably one of most vital phenotypes for bacteria since nearly all cells experience nutrient stress. Persisters are also responsible for many recurring infections. However, how persister cells wake to reconstitute infections is not understood well, beyond that the level of ribosomes governs their waking speed in rich medium. Here, using single cell observations, we determined that alanine as the sole carbon source wakes Escherichia coli persister cells and that persister cells do not wake stochastically but wake primarily when presented with a carbon source. By screening all E. coli proteins, we found that the mechanism of persister cell waking is through sensing nutrients by the chemotaxis and flagellum systems and by reducing levels of the secondary messenger cAMP, which leads to ribosome resuscitation and rescue. Hence, persister cells wake using pathways evolved for nutrient sensing.