Colonization by specific fecal Escherichia coli strains of the vaginal and subsequently the uroepithelial mucosa of susceptible women appears to be one of the early and obligatory events associated with successful microbial invasion of the urinary tract. Our hypothesis is that bacterial adherence to vaginal and uroepithelial mucusa in an important event in the colonization of these surfaces and in the pathogenesis of urinary tract infections. This proposal will identify factors important for adherence associated with bacterial virulence and host susceptibility to urinary tract infections. We will test the hypothesis that fecal E. coli from women with recurrent urinary tract infections, compared to strains from healthy women, demonstrate increased a) in vitro adherence to vaginal epithelial cells from women susceptible to urinary tract infection and b)globoseries glycolipid antigen recognition. Adherence will be determined by radiometric assay. Fecal E. coli from women with urinary tract infections and healthy controls will be tested for: 1) Mannose-sensitive and mannose-resistant adherence to vaginal epithelial cells from patients with urinary tract infections and controls 2) Mannose-sensitive and F9-fimbrial mediated hemagglutination. We will also study the role of bacterial fimbriae in adherence, specifically, the question as to whether fimbriae are present on E. coli as they exist in vivo, prior to growth in the laboratory. Different antigenic types of fimbriae will be isolated and purified, and antibody prepared against each type. The antibody will be used in ELISA competition assays to determine what types of fimbriae are present on E. coli in the urine of patients with active infection. The antibody will also be used in an indirect imunofluorescence assay to study the types of fimbriae present on E. coli attached to uroepithelial and vaginal epithelial cells. Finally, the charge density and hydrophobic characteristics of adherent E. coli will be analyzed in a polymer two-phase partitioning system and by hydrophobic chromatography. The possible correlation between these properties and the presence of fimbriae will be examined. Results of the proposed study should yield important information about bacterial adhesins and epithelial cell receptors instrumental in urinary tract infections and could lead to new approaches to the prevention of urinary tract infection.
