Bacterial adherence to urethral catheters.

Closed sterile catheter drainage has markedly reduced the incidence of nosocomial urinary tract infections. Infections that occur during closed drainage must ascend by colonizing the catheter or urethra. Our study compared adherence by different bacterial species to different catheter surfaces. We found no bacteria adhering to the hydrophilic catheter surface. Of the gram-negative bacteria Proteus mirabilis showed the greatest adherence to the other catheters and it, like most bacteria, showed the most marked adherence to the red rubber catheter.