E. coli infections of the lower urinary tract and their treatment by immunomodulation or combined immunomodulation and antigen therapy.

A model of infection by E. coli 022 of the lower urinary tract in the rat is described. The infection is characterized by the presence in the urine of a large number of E. coli (10(5)-10(7) bacteria per ml). There is pus formation in the urine. A few infected rats also exhibited prostate hypertrophy and the presence of ACB could be detected in some of the latter group. Treatment of the infected rats by the C. granulosum-derived immunomodulator P40, injected intravenously either as a single dose of 1 mg per rat 1 day after infection or as 2 fractionated doses of 0.5 mg 1 day and 3 days after infection resulted in sterilization of a significant number of urines. The interest of fractionating the dose of P40 is to reduce the incidence of prostate hypertrophy formation. Comparable results were obtained when P40 was given preventively to the rats either as a single dose 7 days before infection or as 2 fractionated doses 7 days and 1 day before infection. The association of a single preventive dose of 1 mg of P40 given 7 days before infection by administering a suspension of heat-killed E. coli 022, as a specific antigen, 1 day after infection permitted the sterilization of urines in all infected rats and prostate hypertrophy formation did not occur.