Role of S- and common-type I-fimbriae of Escherichia coli in experimental upper and lower urinary tract infection.

Fimbrial antigens are very often associated with pathogenic Escherichia coli strains, especially those which cause extraintestinal infections. These fimbriae have the ability to agglutinate erythrocytes {hemagglutination) and can be further grouped according to their receptor specificity. P-fimbriae recognize the 2-D-Gal-{1 -4)-ß-D-Gal region of globotetraosylceramide and trihexosylceramide, which are antigens of the human blood group P system. P-fimbriated E. coli are predominant in upper urinary tract infections {UTI) in man. ln contrast, S-fimbriae recognize a sialic acid-containing structure as receptor and are often associated with neonatal meningitis and, to a lesser extent, with UTI.· Mannose-sensitive hemagglutination fimbriae {Pili, also termed common type I fimbriae) use a mannose-containing receptor and are therefore inhibited in their hemagglutination capacity by the presence of mannose. These fimbriae are widespread among E. coli trom different sources.4·5 Most pathogenic E. coli strains express more than one fimbrial type on their cell surface• {Boulnois & Jann, personal communication). Therefore it is hard to define the exact roJe of one single adhesin factor in infectious disease. ln order to overcome this problern we have cloned the genetic determinants fort the S-fimbrial adhesin (sfa) 8 and for common type I fimbriae (pil) (Hacker et al., in preparation) and introduced the recombinant DNAs in a non-fimbriated E. coli 06 strain. The two isogenic E. coli strains, which only differed in their fimbrial type and in an antibiotic recognition marker were tested in a rat UTI model, which has been shown fo fulfill the criteria for a persistent infection.9