Figure 6
B. pseudohinzii (strain 3227) attaches to and intermingles with cilia in an in vitro-infection model. Tracheal explants were cultured for 24 h, with following addition of bacteria for 4 h (a–i) or 24 h (j–r). (a–c) Semithin sections of tracheal explants cultured for 24 + 4 h, light microscopy. (a) Without adding of bacteria, cilia are normally orientated and no bacteria are visible. (b) B. pseudohinzii (0.4 × 104 CFU) was added for 4 h. No bacteria are seen. (c) B. pseudohinzii (2.3 × 108 CFU) was added for 4 h. Bacteria attach to cilia (dotted arrows). (d–i) Transmission electron microscopy. (d,g) Control experiment. Tracheas were cultured for 24 + 4 h without bacteria. Cilia appear normal in length and orientation. No signs of cell damage. (e,h) No obvious difference to controls 4 h after incubation with 0.4 × 104 CFU B. pseudohinzii. (f,i) B. pseudohinzii (2.3 × 108 CFU) was added for 4 h. Bacteria are located between the cilia (dotted arrow), (j,m,p) Control. Explants cultivated for 24 h without bacteria demonstrate unaltered ciliated cells in light (j) and transmission electron microscopy (m,p). (k,n,q). B. pseudohinzii (0.4 × 104 CFU) was added for 24 h. Bacteria (dotted arrows) intermingle with kinocilia. They are not seen at non-ciliated cells. (l,o,r) B. pseudohinzii (2.3 × 108 CFU) was added for 24 h. The number of bacteria (dotted arrows) is increased, cells with shortened of cilia can be observed in transmission electron microscopy (o,r).
