The Pathogenesis of Shigella Diarrhea. II. Enterotoxin-induced Acute Enteritis in the Rabbit Ileum

Abstract

Shigella dysenteriae 1 enterotoxin inoculated into ligated ileal loops of rabbits produced alterations and extrusion of villous epithelial cells as early as 1 hr after challenge. By 6 hr epithelial cells were cuboidal rather than columnar; the villi were shortened with a decreased villus-to-crypt ratio and with many intact or degenerating transmigrating lymphocytes. Neither Vibrio cholerae enterotoxin nor heat-inactivated shigella toxin caused any detectable alterations in the mucosal architecture. These data indicate that S. dysenteriae 1 enterotoxin is cytotoxic to the intestinal epithelial cell in vivo. The changes induced are similar to those previously found after oral challenge of guinea pigs with live, virulent Shigella flexneri 2a. These results suggest that some of the virulence of Shigella species in the gastrointestinal tract may be mediated by cell-free toxins. They further serve to distinguish the mode of action of shigella enterotoxin from that of cholera enterotoxin.