VIRULENCE CHARACTERISTICS OF ESCHERICHIA-COLI IN RELATION TO HOST RESPONSE IN MEN WITH SYMPTOMATIC URINARY-TRACT INFECTION

To assess virulence properties in uropathogenic Escherichia coli isola tes from men with symptomatic urinary tract infection (UTI), we analyz ed 88 urinary isolates from men with acute pyelonephritis (n = 41), fe brile UTI without clinical signs of renal infection (n = 33), or acute cystitis (n = 14) for O:K:H serotype, P fimbriae, and production of h emolysin and aerobactin. In the three diagnostic groups, 88%, 67%, and 79% of the strains, respectively, were represented by 10 O antigen gr oups commonly associated with acute pyelonephritis in women and childr en. Fifty-eight different O:K:H serotypes could be identified, of whic h O18ac:K5:H- predominated (n = 8). There was a higher frequency of he molytic strains among patients with pyelonephritis (73%) and febrile U TI (76%) and a lower frequency of P-fimbriated strains (56% and 45%, r espectively) and aerobactin-positive strains (51% and 39%, respectivel y) among these patients than was previously encountered in women and c hildren with uncomplicated acute pyelonephritis. The distribution of b acterial properties was unrelated to patient age and underlying compli cating factors. The findings suggest differences in host-parasite rela tionships between men and women with symptomatic UTI caused by E. coli .