Listeria monocytogenes is a bacterial pathogen which invades and multiplies within non-professional phagocytes. Signaling cascades involved in cellular entry have been extensively analyzed, but the events leading to vacuolar escape remain less clear. In this chapter, we detail a microscopy FRET-based assay which allows quantitatively measuring L. monocytogenes infection and escape from its internalization vacuole, as well as a correlative light/electron microscopy method to investigate the morphological features of the vacuolar compartments containing L. monocytogenes.
Keywords: CCF4; Correlative light/electron microcopy (CLEM); Förster resonance energy transfer (FRET) microscopy; Listeria monocytogenes; Listeriolysin O; Phagocytosis; Phospholipases; Vacuole.