Fig 2.

Epithelial cell invasion in the absence of SapA. NHBE cell monolayers (A) were inoculated with the parent strain (B) or the sapA mutant strain (C), incubated for 24 h, and monitored for colonization by fluorescence microscopy. NTHI cells were labeled with a anti-OMP antibody and detected by anti-rabbit FITC antibody (green). Epithelial cell membranes were stained with wheat germ agglutinin conjugated to Alexafluor 594 (red), and DNA was counterstained with Hoechst 34580 (white). Arrows indicate cytoplasmic NTHI.