Title: The virulence factor of <i>Escherichia coli</i> in urinary tract infection
Abstract: Bacterial properties of Escherichia coli isolated from patients with acute uncomplicated infections were examined mainly to clarify the significance of fimbriae as the virulence factor of E. coli in urinary tract infections. Type I fimbriae were a colonization factor to transitional cells in the urinary tract and simultaneous presence of type II fimbriae including P is considered to be one of the most important virulence factors in genitourinary infections.Since the next step of our experiment was the analysis of vilurence factors in vivo, we developed a new experimental system using mouse. By using this system, we belive that the significance of phase variation between type I and type II fimbriae and the relationship of each virulence factor can be elucidated.