An indwelling urinary catheter is a thin, hollow tube inserted through the urethra into the urinary bladder to collect and drain urine. Once inserted, a balloon is inflated which keeps the catheter in place. An indwelling urinary catheter may be left in place for a period of days to weeks. The catheter is connected to a drainage bag that has a valve that can be opened to release urine as well as a separate port that can be used to collect a urine sample.

Multifaceted Approach

Urine culture stewardship is a multifaceted approach to ensure that urine cultures are:

  • Performed only when appropriate indications are present in order to determine if treatment with antibiotics is indicated
  • Collected, stored, and processed in a manner to best prevent contamination with microorganisms such as bacteria

This approach can be used in patients with and without indwelling urinary catheters in a variety of settings.

Figure: Biofilm on Indwelling Catheter


Scanning electron micrograph of S. aureus bacteria on the luminal surface of an indwelling catheter with interwoven complex matrix of extracellular polymeric substances known as a biofilm. Credit: CDC Public Health Image Library.


Indwelling urinary catheters quickly become colonized with microorganisms after insertion. These microorganisms produce proteins and other substances that are sticky and facilitate the formation of biofilms. These biofilms make it impossible to eradicate the bacteria even with antibiotics.


Bacteriuria is the presence of bacteria in urine. Because indwelling urinary catheters become colonized so easily, the incidence of bacteriuria is 3-7% per day. Nearly 100% of patients with urinary catheters will have bacteriuria after one month.

Catheter-associated Asymptomatic Bacteriuria (CA-ASB)

CA-ASB is the presence of bacteria in a urine sample due to bacterial colonization of the urinary tract and/or indwelling urinary catheter. CA-ASB does not cause symptoms and is not indicative of an infection that needs treatment with antibiotics in most patients; it is appropriate to treat ASB with antibiotics in pregnant women and in those undergoing certain invasive urological procedures.

Catheter-associated Urinary Tract Infection (CAUTI)

A CAUTI occurs when germs (usually bacteria) enter the urinary tract through the urinary catheter and cause symptoms. CAUTIs have been associated with increased morbidity, mortality, healthcare costs, and hospital length of stay. They require treatment with antibiotics.

Is it CA-ASB or CAUTI?

Distinguishing between CA-ASB and CAUTI is important to avoid unnecessary antibiotic use. Studies have shown that inappropriate treatment of patients with urinary catheters and ASB is widespread and can lead to unintended consequences.

Pitfalls of unnecessary antibiotic overuse are numerous and include

  • Clostridioides difficile infections
  • Colonization or infection with resistant bacteria
  • Adverse drug events
Advantages of Urine Culture Stewardship

Institutions that have implemented urine culture stewardship have reported:

Decreases in

  • the number of total urine cultures ordered
  • the number of ASB cases treated inappropriately
  • costs related to overtreatment of ASB
  • CAUTIs


No increases in

  • patient adverse events
Developing a Urine Culture Stewardship Program

A method is presented for designing and implementing a urine culture stewardship program for hospitalized patients with indwelling urinary catheters.

This information could be used by a number of different healthcare personnel from infection preventionists looking to establish a multidisciplinary program across a healthcare system to individual providers searching for ideas to improve patient safety on a single unit.

Designing and implementing a urine culture stewardship program includes:

  • Survey
    current practices and outcomes to determine the potential benefit of urine culture stewardship for your institution.
  • Structure
    your program for success.
  • Strategize
    initiatives you can incorporate into your program
  • Sustain
    reductions achieved with your program.
Urine Stewardship Arrow: Survey, Structure, Strategize, Sustain