Urine is commonly believed to be sterile until it reaches the urethra but that has led to numerous misconceptions about what can and should or should not be done with it. Drinking urine is a bad idea, for example, because even though it is sterile it contains urea and other substances that can still be toxic.

Obviously a bladder infection has always been the qualifier in sterile urine but another study has found bacteria in the bladders of healthy women, which forces a rethink of bladder health and disease. Researchers evaluated urine specimens collected directly from the bladder through an aspiration or a catheter to avoid contamination. These specimens were analyzed using an expanded quantitative urine culture (EQUC) technique that identifies bacteria not detectable by the standard urine culture techniques typically used to diagnose urinary tract syndromes. This study also used 16S rDNA sequencing to classify bacterial DNA.

"While traditional urine cultures have been the gold standard to identify urine disorders in the past, they do not detect most bacteria and have limited utility as a result," said Alan Wolfe, PhD, lead author and professor in the Department of Microbiology&Immunology at Loyola University. "They are not as comprehensive as the testing techniques used in this study."

Through their analysis, the researchers found that certain bacteria in the female bladder may contribute to symptoms of urinary incontinence. They also revealed that some bacteria are more common in women with urgency urinary incontinence than in healthy women.

"If we can determine that select bacteria cause various lower urinary tract symptoms, we may be able to better identify those women at risk and more effectively treat them," said co-author Linda Brubaker, MD, MS, of Loyola University Chicago Stritch School of Medicine.

Published in European Urology.