Studies on the virulent factor of Escherichia coli isolated from urogenital infection--pilus type and adherence to human exfoliated uroepithelial cells etc

One hundred and twenty three strains of Escherichia coli isolated from the urine of patients with urogenital infections and 55 strains isolated from the fecal samples of healthy individuals were assayed for 0 antigen and hemolysin production as virulence factors, and for pilus type and in vitro tests of adhesion to human exfoliated uroepithelial cells as colonization factors. The incidence of MS pili in Escherichia coli isolated from patients with acute uncomplicated cystitis, chronic complicated cystitis, acute uncomplicated pyelonephritis and acute prostatitis was 60.9%, 22.7%, 87.5%, 68.2% and 30.9%, respectively. The incidence of P pili was 69.7%, 51.2%, 62.5%, 54.5% and 25.5%, respectively. The strains showing haemolysin production had MS pili and P pili, which show strong virulence. MS pili strains and P pili strains isolated from the patients with acute uncomplicated cystitis and acute uncomplicated pyelonephritis adhered to human exfoliated uroepithelial cells well. Consequently, the pilus type might be the most significant colonization factor in uncomplicated urogenital infection which is shown by the normal defense mechanism in host side.