FIG. 5.

Hypothetical model of X. fastidiosa colonization in leafhopper vectors. (A) Cells initially attach laterally to the cuticle of insects, a process mediated by HxfA, HxfB, and possibly other carbohydrate-binding proteins. Microcolonies are established (B) and change in morphology (C), with cells in the center becoming polarly attached to increase the exposed surface area; type I pili may be important for polar attachment. (D) Mature biofilm, with newly divided daughter cells not attached to the leafhopper cuticle being subject to detachment from the biofilm. Scanning electron microscope pictures are unpublished images obtained in a previous study (2).