Diagnostic criteria and natural history of catheter-associated urinary tract infections after prostatectomy.

Bacteriuria occurred postoperatively in 28 of 122 patients who had sterile urine before transurethral prostatectomy without antibiotic prophylaxis. Prospective monitoring of catheter bacteriuria indicated that a bacterial count of 10(3) colony-forming-units (cfu/ml progressed to significant infection except when the bacterium in the urine was Staphylococcus epidermidis. Bacteraemia developed in 4 bacteriuric patients, including 2 in whom the bacteria in the urine and blood were mixed. Catheter removal without antibiotic therapy resulted in spontaneous resolution of Staph epidermidis bacteriuria in 9 patients but infection persisted in 5 of 6 patients with other bacteria in the urine. This study indicates that a bacterial count of 10(3) cfu/ml in catheter urine is associated with pathological sequelae and that catheter removal does not result in resolution of bacteriuria caused by pathogenic bacteria.