A molecular analysis of Escherichia coli cell surface antigens required for the colonisation of the urinary tract.

The uropathogenic Escherichia coli strain 20025 (04:K12:H-) elaborates at least four fimbrial antigens, Fy (F14), F12-rel, F13, F1C and secretes the toxin a-haemolysin. The work presented in this thesis demonstrates that the gene clusters encoding these five determinants are located within a 60-70kb region of the 20025 chromosome. The F14 fimbrial antigen produced by 20025 is a novel P-fimbriae serotype and exhibits a different binding specificity to the majority of P-fimbriae. To determine the basis of this apparent difference in cell surface receptor specificty a detailed molecular analysis of the F14 gene cluster is presented. The cloning and analysis of two other Escherichia coli surface antigens, the non-fimbrial adhesin NFA-1 and the K12 capsular polysaccharide is also described.