What results from a urine culture can confirm a urinary tract infection?

The isolation of significant bacteria from a urine culture is the definitive result that can confirm a urinary tract infection (UTI). A urine culture involves taking a urine sample and allowing any microorganisms present to grow in a controlled environment. If bacteria are isolated in quantities considered significant (usually defined as 100,000 colony-forming units per milliliter or more), this indicates an active infection in the urinary tract.

The presence of bacteria in the culture is a direct indicator of infection, distinguishing it from potential contaminants. Other factors, such as glucose presence or high protein levels, can be associated with different medical conditions but do not specifically confirm a UTI. Similarly, a decrease in urine volume may suggest various renal or systemic issues but is not a direct marker for a urinary tract infection. Thus, confirming a UTI relies primarily on the isolation of significant bacteria from a properly collected urine sample.