Antigenic phenotypes of Escherichia coli in urine from patients with urinary tract infections.

Various antigenic phenotypes of Escherichia coli in urine were analysed using monoclonal antibody against pyelonephritis-associated P-pili (PAP-pili), and polyvalent O- and K1-antisera, and the results were compared with the clinical diagnosis. PAP-pili, O1- and K1-positive E. coli were isolated more frequently in urine from patients with acute pyelonephritis. E. coli found in urine from patients with recurrent pyelonephritis were frequently PAP positive. Based on the antigenic phenotypes of strains in urine, it is suggested that pyelonephritopathogenic strains may originate from a small number of clones.