In vitro binding of type 1-fimbriated Escherichia coli to uroplakins Ia and Ib: Relation to urinary tract infections

Urinary tract infections, caused mainly by Escherichia coli, are among the most common infectious diseases. Most isolates of the uropathogenic E. coli can express type 1 and P fimbriae containing adhesins that recognize cell receptors. While P fimbriae recognize kidney glycolipid receptors and are involved in pyelonephritis, the urothelial receptors for type 1 fimbriae were not identified. We show that type 1-fimbriated E. coli recognize uroplakins Ia and Ib, two major glycoproteins of urothelial apical plaques. Anchorage of E. coli to urothelial surface via type 1 fimbriae-uroplakin I interactions may play a role in its bladder colonization and eventual ascent through the ureters, against urine flow; to invade the kidneys.