<i>E</i>. <i>histolytica</i> disrupts the colonic epithelium in germ-free mice.

Colonic loops inoculated with Eh in specific pathogen-free (SPF) and germ-free (GF) mice were fixed in Carnoy’s solution and stained with periodic acid-Schiff reagent. (A) Representative images of SPF animals inoculated with Eh showing thick adherent inner mucus (IM) layer and a loose outer mucus (OM) layer, with a cavitated goblet cell (GC; arrow) due to mucus depletion shown. (B) Intense mucus secretion in response to Eh in GF (arrows) mice; note the lower number of goblet cells in the surface epithelium and crypts. (C) Eh attaching to GF colonic epithelial cells (EC) (arrows), the epithelial cell on the right appear to be plucked out (inset) by Eh. (D) The arrows point at disruption of the single layer of epithelial cells by Eh in close proximity to the erosion.