Resolution of induced urinary tract infection: an animal model to assess bladder immunization.

The resolution of an Escherichia coli urinary tract infection in the bladder and kidneys of control and immunized rats was used to assess their resistance to experimentally induced infection. Prior intravesical immunization of rats with formalin killed E. coli 06 resulted in faster resolution of an infection that had been induced with viable E. coli 06 than was observed in nonimmunized controls. The faster resolution of infection after immunization correlates with our previous findings of decreased adherence of bacteria to urothelium of immunized rats and supports the hypothesis that local immune responses in the urinary tract may play a role in resistance to recurrent urinary tract infections.