Figure 4.

TEM sections of HIBCPP cells grown in the inverted cell culture system infected with indicated NTHI and H. influenzae isolates for 6 h. (A–F) TEM images of intracellular bacteria (black arrow), which invaded from the blood facing side. (B) Different phases of the pathogenesis progress—bacteria adhering to HIBCPP cells, invading into HIBCPP cells and already intracellular of a HIBCPP cell. Scale bars represent 1 µm. inv, invaded; adh, adherend; int, intracellular. “p+” means fimbriated and “p−“ means non-fimbriated.