Role of intestinal surfactant-like particles as a potential reservoir of uropathogenic Escherichia coli

The binding of uropathogenic Escherichia coli is mediated at the tips of pill by the PapG adhesin, which recognizes the Gal alpha(1-4)Gal disaccharide on the uroepithelial surface. These receptors have been identified unequivocally in the human and murine urinary tracts but not in intestinal epithelium, yet uropathogenic E. coli strains are commonly found in normal colonic microflora. The gastrointestinal tract from duodenum to rectum elaborates a phospholipid-rich membrane particle with surfactant-like properties. In these studies, we report that purified murine particles contain a receptor recognized by the class I PapG adhesin because: (1) PapD-PapG complexes and class I pill bound to surfactant-like particles in a solid-phase assay, whereas binding was not detected in microvillous membranes derived from the same tissues, (2) purified PapD-PapG complex bound to a glycolipid receptor detectable in lipid extracts from the particles, and (3) soluble Gal alpha(1-4)Gal inhibited the adhesin by 72% from binding to surfactant-like particles. The Gal alpha(1-4)Gal receptor present in the intestinal surfactant-like particle which overlies the intestinal mucosa could provide one means to establish an intestinal habitat for uropathogenic E. coli. (C) 2000 Elsevier Science B.V. All rights reserved.