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

Abstract

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 identifled. We show that type 1-fimbriated E. coli recognize uroplakins Ia and Ib, two major glycoproteins ofurothelial 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.Urinary tract infections are among the most common infectious diseases, accounting for almost 5 million cases annually and causing considerable morbidity and mortality (1). Increasing incidence of antibiotic-resistant E. coli, which causes up to 95% of these infections, calls for additional therapeutic considerations. One useful approach entails the inhibition of bacterial attachment to urothelial surface, a crucial initial event involving precise interactions between a group of bacterial adhesive molecules called adhesins and their cognate urinary tract receptors (2-4). Knowledge of the molecular details of the receptor-adhesin interface may provide a basis for rational drug design for preventing and treating urinary tract infections.To facilitate attachment to eukaryotic receptors, E. coli assemble fimbriae capped with adhesin molecules (5-7). Two major classes of fimbriae of uropathogenic E. coli have been functionally defined. The P fimbriae are expressed in "70% of the pyelonephritis isolates, and they bind to the Gala(1-4)Gal moiety in the glycolipid receptors (8). The type 1 fimbriae are expressed by more than 90% of the uropathogenic E. coli, and they can bind, via mannose moieties, to the urothelial surface (9-11). Immunohistochemical staining of voided urothelial cells of urinary infection patients showed adhering E. coli with type 1 fimbriae alone (12). Animal studies showed that E. coli expressing type 1 fimbriae, but not those harboring mutated ones, can cause urinary tract infections (13,14). These results clearly establish the functional importance of the mannosesensitive type 1 fimbriae in urinary tract infections. Virtually nothing is known, however, about the urothelial receptors that presumably bear the mannoses recognized by the type 1 fimbriae. Consequently, the precise role of this kind of fimbriae and their functional relationship with the P fimbriae in various types of urinary tract infections are not well understood (2-7, 15).Significant progress has recently been made to characterize biochemically the apical surface of mammalian urothelium, which is covered with nunmerous rigid-appearing, 0.3-to 0.5-,um plaques. In cross-sections, the luminal leaflet of the plaque membrane is twice as thick as the cytoplasmic leaflet, hence the term asymmetrical unit membrane (...

Antimicrobial activity of menthol modified nanodiamond particles

“…More recently, the antibacterial activity of diamond particles [36], [37] and [38] and their potential to interfere with biofilm formation [1] have been highlighted. The underlying anti-adhesive strategy proposed was based on the interfering with type 1 fimbriae-mediated mannose recognition events [39]. Such biofilm disrupting activity had not been observed previously for other glyco-nanoparticles (glyco-NPs) such as glycofullerenes, goldbased glyco-NPs or for other multivalent mannose-derived molecules [2] and [40].…”

The Pathogenesis of Urinary Tract Infections

“…An inflammatory process occurs shortly after this binding process has been initiated. A number of studies have demonstrated that interactions between the Fim H adhesin and epithelial cells on the bladder's surface are essential for colonisation and www.intechopen.com infection of bladder epithelium with strains of uropathogenic E. coli (Sun 1996, Wu et al 1996. This specific 'adhesin-epithelial cell' binding process occurs when type 1 pili bind to uroplakin 1a (UP1a) and uroplakin 1b (UP1b) (Malaviya and Abraham 1998).…”

Comprehensive mutagenesis of thefimSpromoter regulatory switch reveals novel regulation of type 1 pili in uropathogenicEscherichia coli

“…They are caused mainly by uropathogenic Escherichia coli (UPEC), which rely on several virulence factors to cause disease (2); type 1 pili (T1P) are perhaps the most important of these (3). T1P present a tip adhesin, FimH, that binds specifically to mannose, which is found on several glycosylated surface proteins, such as uroplakins and α1-and β3-integrins (4,5), in the mammalian bladder. Binding to mannosylated proteins initiates a cascade of events including UPEC invasion of host tissues (2), formation of intracellular structures (6), and activation of the host immune response (7).…”