FIG 6 .

K. kingae adherence to human epithelial cells involves sequential adhesive events. Initial K. kingae interactions with the host respiratory epithelium are initiated by type IV pili (1). Once pili have engaged their host cell receptor, PilT-mediated pilus retraction pulls the bacterium into close contact with the host cell membrane. This action results in physical displacement of the polysaccharide capsule, exposing Knh to the host cell membrane. Unmasked Knh can then mediate high-affinity K. kingae interactions with human epithelial cells via the Knh host cell receptor without the need for genetic capsule downregulation (2).