FIG 4.
Correlative light-electron microscopy of cdrAon bacteria in vacuoles. Fluorescence and electron micrographs of human corneal epithelial cells at 6 h after inoculation with PAO1F expressing cdrA-GFP. Extracellular bacteria were killed 3 h postinfection with amikacin (200 μg/mL), and amikacin (200 μg/mL) and ofloxacin (1 μg/mL) were then added for a further 3 h. Cells were fixed at 6 h, and fluorescence microscopy was performed before preparing cells for electron microscopy (EM). Red boxes show corneal epithelial cells with corresponding EM micrographs. Black dotted boxes indicate regions from which the respective insets were taken to show bacteria within vacuoles with evidence of vacuolar membranes.