Fig. 2

Localization of intracellular NTHi. BEAS-2B cells were infected with NTHi strain ATCC 19418 for 2 hours. After killing extracellular bacteria with gentamicin, epithelial cells and bacteria were stained with several fluorescent dyes and Hoechst (blue). a Representative fluorescent micrographs of intracellular NTHi (blue) and epithelial cells stained with early endosomal marker (EEA-1, red). White arrows show EEA-1-positive regions, and white arrowheads show NTHi. For a detail of merged image, see a top-right inset. b Representative fluorescence micrographs of intracellular NTHi (blue) and epithelial cells stained with late endosomal marker (LAMP-1, purple). White arrows show LAMP-1-positive regions, and white arrowheads show NTHi. For a detail of merged image, see a top-right inset. c Representative fluorescent micrographs of intracellular NTHi and epithelial cells stained with LIVE/DEAD® (green) and cells were stained with acidic lysosomal dye (LysoTracker® Red). White arrows show LysoTracker® Red-positive acidic organelles, and white arrowheads show NTHi. Fluorescent micrographs were taken at 2,000× magnification. White bars represent 5 μm. Another strain (HUSM 0481) was also tested and similar results were obtained