Entrance of Bacteria into the Female Urinary Bladder

Abstract
Although bladder urine is normally sterile, it seems likely that small numbers of bacteria may enter the bladder commonly in women, especially in association with trauma to the urethra. Our investigation was undertaken to study bladder urine from women without urinary-tract infection and to determine the effect of mild urethral trauma (urethral milking) on isolation of bacteria from bladder urine.