Increased severity of urinary tract infection and bacteremia in mice with urinary bladder injury induced by cyclophosphamide.

The effect of cyclophosphamide on urinary tract infection was studied, using Pseudomonas aeruginosa in a murine model. Urinary tract infections were produced by injecting P. aeruginosa through a urethral catheter into the bladders of mice. The number of P. aeruginosa organisms in the bladder tissue and kidneys, histopathology, peripheral leukocyte count, and antibody response to P. aeruginosa was measured. The local effect of cyclophosphamide on the bladder was determined by measuring the bladder tissue water and examining the histopathology. Cyclophosphamide increased the susceptibility of mice to P. aeruginosa urinary tract infection, resulting in marked cystitis and an increase in renal infection, bacteremia, and mortality. These changes correlated with the toxic effect of cyclophosphamide on the wall of the bladder rather than with peripheral leukopenia or failure of antibody response.