Urine Colony Count Unit Converter

A urine colony count is the number of bacterial colonies grown from a urine sample, reported in colony-forming units per milliliter (CFU/mL). It is the primary way to confirm whether bacteria in the urinary tract represent a true infection or harmless contamination.

A urine culture involves placing a measured amount of urine on growth media and incubating it, typically for 24 to 48 hours. The laboratory then counts the colonies that appear. A count of 100,000 CFU/mL or more from a clean-catch midstream specimen is the traditional threshold for significant bacteriuria in symptomatic patients.

The result also identifies which organisms are present and, when counts are significant, guides antibiotic sensitivity testing to help choose the right treatment.

The bacteria measured by a colony count originate from organisms that have entered the urinary tract, most commonly ascending from the perineal and periurethral area into the bladder. The most frequent source is the gastrointestinal tract, particularly Escherichia coli and other enteric bacteria.