The predominant form of life for the majority of microorganisms in any hydrated
biologic system is a cooperative community termed a "biofilm." A biofilm on an indwelling
urinary catheter consists of adherent microorganisms, their extracellular products, and host components deposited on the
catheter. The biofilm mode of life conveys a survival advantage to the microorganisms associated with it and, thus, biofilm on
urinary catheters results in
persistent infections that are resistant to antimicrobial
therapy. Because chronic catheterization leads almost inevitably to
bacteriuria, routine treatment of asymptomatic
bacteriuria in persons who are catheterized is not recommended. When symptoms of a
urinary tract infection develop in a person who is catheterized, changing the
catheter before collecting urine improves the accuracy of urine culture results. Changing the
catheter may also improve the response to
antibiotic therapy by removing the biofilm that probably contains the infecting organisms and that can serve as a nidus for
reinfection. Currently, no proven effective strategies exist for prevention of
catheter-associated
urinary tract infection in persons who are chronically catheterized.