Persisters of Bacterial Biofilms

Bacterial biofilms are associated with increased ability to withstand antibiotics, making it extremely difficult to treat biofilm-related infections. This chapter focuses on a unique subpopulation of bacterial biofilms, persisters, which are highly tolerant to lethal doses of antibiotics. It has been recognized that antibiotic-tolerant biofilm persisters are closely linked with recalcitrance and relapse of infectious diseases. Biofilms contribute to physiological heterogeneity of the community and offer a protective environment suitable for the formation and survival of persisters. Current evidence suggests that biofilm persisters adopt a series of molecular mechanisms to generate antibiotic tolerance. They may enter into a dormant state with reduced growth and metabolic activities, while maintaining essential biological processes such as stress responses and efflux pumps. When exposed to high concentrations of antibiotics, the majority of biofilms can be killed and only persisters survive. This raises the hypothesis that persisters are the responsible subpopulation for the antibiotic tolerance of biofilms. Therefore, targeting biofilm persisters represents a promising strategy for combatting biofilm-related infections. This chapter presents evidence supporting the clinical relevance of bacterial biofilms persisters, the uncovered mechanisms behind their antibiotic tolerance, and the development of approaches to combat bacterial biofilm infections by targeting persisters.