Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium

Figure 4

Respiratory epithelium of the nasal septum that was exposed to P. multocida A UN001 (treatment 2). MET and gold-labeling of LPS using a lectin of Limulus polyphemus. (a) Bacterial structure with positive labeling on the outer membrane (thin arrow). Note the abundant capsule that surrounds each bacteria. Bacterial culture. (b) Note the interface of the LPS between the bacterium (B) and microvilli (thin arrow). Some LPS is free in the lumen admixed with amorphous material but is also visible at the surface of some microvilli. Microvilli (MV) of a ciliated epithelial cell (CE) and cilia (thick arrows). (c) This particular bacterium has lost its capsule (arrow) compared with three other bacteria (B). (d) Thread-like bilaminar structure (thick arrow) located in the lumen of the nasal septum that is positively labeled with LPS (thin arrows). (e) Multiple thread-like LPS-positive bilaminar structures are associated with the cytoplasmic membrane and microvilli of an ciliated epithelial cell (CE) (black arrows); some gold particles seem to ingress into the cell (white arrow). (f) A bilaminar structure bridges two cilia (black arrow), and similar thread-like bilaminar structures bridge the cilia and the cytoplasm of the same cell where the base of a cilia was not included (red arrow); large numbers of gold particles are already present within the cytoplasm of the same cell (arrowheads).

(a)

(b)

(c)

(d)

(e)

(f)