P-fimbriated Escherichia coli urinary tract infection: a clinical correlation.

We designed a retrospective study to determine the incidence of P-fimbriated Escherichia coli in patients with asymptomatic bacteriuria, acute urethral syndrome, bacterial cystitis, acute pyelonephritis, possible acute pyelonephritis, and acute and chronic prostatitis. In addition, we compared the incidence in uncompromised vs compromised hosts, inpatients vs outpatients, and children vs adults. P-fimbriated E coli were isolated in more than 80% of uncompromised patients with either acute pyelonephritis or acute prostatitis. In clinically compromised patients having these disorders, the incidence dropped to approximately 30% (P less than .025). Neither age nor inpatient/outpatient status was a significant factor. We stress the importance of P-fimbriation as a virulence factor in acute pyelonephritis and acute prostatitis caused by E coli, though these diseases may be caused by less virulent organisms in compromised patients. Thus, patients with acute pyelonephritis or acute prostatitis caused by E coli negative for P-fimbriae probably should be considered compromised; the compromising factor should be determined as a guide to subsequent treatment.