Studying Bacterial Persistence: Established Methods and Current Advances

To date, we are living in a postantibiotic era in which several human pathogens have developed multidrug resistance and very few new antibiotics are being discovered. In addition to the problem of antibiotic resistance, every bacterial population harbors a small fraction of transiently antibiotic-tolerant persister cells that can survive lethal antibiotic attack. Upon cessation of the treatment, these persister cells wake up and give rise to a new, susceptible population. Studies conducted over the past two decades have demonstrated that persister cells are key players in the recalcitrance of chronic infections and that they contribute to antibiotic resistance development. As a consequence, the scientific interest in persistence has increased tremendously and while some questions remain unanswered, many important insights have been brought to light thanks to the development of dedicated techniques. In this chapter, we provide an overview of well-established methods in the field and recent advances that have facilitated the investigation of persister cells and we highlight the challenges to be tackled in future persistence research.