Escherichia coli is a type of bacteria that can enter the urinary tract through the urethra, says WebMD. The bacteria is common to the human digestive system, and cross-contamination of the urinary tract, which consists of the kidneys, bladder, ureters and urethra, can occur due to poor hygiene practices.
In both males and females, the extraintestinal pathogen uropathogenic Escherichia coli, also called UPEC, is the most common cause for urinary tract infections, states the Centers for Disease Control and Prevention. E. coli contamination can cause urinary tract infections in an ascending manner. That is, the bacteria travel up the urinary tract, through the urethra and into the bladder. From there, the infection can spread through the ureters to the kidneys and into the bloodstream, potentially causing life-threatening illness.
In females, urinary tract infections caused by E. coli contamination can occur due to contamination of the urethra by feces, explains Everyday Health. Unlike males, there is no substantial protective barrier between the urethra and the anus in females, and the close proximity of the two orifices lends to a higher chance of cross-contamination by E. coli residing in the intestinal flora. Incidences of urinary tract infections are not equal between men and women. On average, women are four times more likely than men to develop a urinary tract infection during their lifetime.