RESUMEN
Forty patients undergoing transurethral prostatectomy were randomized prospectively into a controlled study to determine the influence of prophylactic piperacillin (4 X 2 g for 48 h) on the postoperative course. Samples of urine, prostate, urethral swabs and faeces were cultured to determine the origin of infection and to record the development of resistance and selection of the intestinal flora. Piperacillin lowered the incidence of early postoperative urinary tract infection (UTI) (P less than 0.01), of fever (P less than 0.05) and the occurrence of reinfection within three weeks postoperatively (P less than 0.01). The organisms causing early UTIs and reinfections originated mainly from the prostate and urethra in the immediate perioperative period and were both Gram-positive (40%) and Gram-negative (60%); those causing late UTIs in previously uninfected patients originated from faecal flora and were mainly Gram-negative (92%). Prostatic levels of piperacillin were 30.3 +/- 29.2 mg/g; the ratio serum: prostate was 1;0.27. There was no development of resistance to piperacillin or selection of resistant strains in intestinal or urogenital flora. Except for a significant increase of Candida albicans, piperacillin did not influence numbers or composition of aerobic and anaerobic bacteria in the intestinal flora.