FIG. 6.

Micrographs of an infected sand fly anterior midgut at 7 days postfeeding. (A) Intact anterior midgut showing a brownish-black bloodmeal by phase-contrast microscopy (100 × magnification; scale bar = 140 μm). In certain flies, the bloodmeal was completely absent at this time point. Fluorescence microscopy revealed relatively low densities of GFP⁺ B. ancashensis cells at 7 days, especially in the (B) posterior portion of the anterior midgut. (C) A microcolony was still apparent at the anterior end of the anterior midgut (400 × magnification; scale bar = 35 μm in B, C).