A small subpopulation of non-replicating, multidrug-tolerant bacteria is present within clonal populations of many bacterial species. Known as persisters, these bacteria are probably the cause of relapsing infections such as typhoid fever. Formation of non-growing Salmonella persisters is stimulated by macrophage phagocytosis. This chapter outlines methods to identify and study persisters resulting from interactions between bacterial pathogens and their hosts. We use their antibiotic tolerance for isolation and enumeration and developed a method to study the heterogeneity of growth within clonal populations through single-cell analysis.
Keywords: Bacterial pathogen; Fluorescence dilution; Macrophages; Persisters; Salmonella; Single-cell analysis.