Recurring Urinary Tract Infections May Play A Role In Bladder Cancer

Woman suffering from abdominal pain. (Photo by: BSIP/Universal Images Group via Getty Images)

Researchers have known that the presence of E.coli bacteria is responsible for the most common outpatient infections —urinary tract infections (UTIs) —that have a lifetime incidence of around 60 percent in women. A recent study published in PLOS Pathogens has found that a DNA-damaging bacterial toxin called colibactin is produced in people with UTIs.

The researchers further discovered that uropathogenic E.coli strains —that cause 80 percent of all UTIs— and the archetypal E. coli strain UTI89 were found to produce colibactin.

Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting approximately 150 million individuals each year. The severity of these infections ranges from asymptomatic to developing sepsis if left untreated over a period of time, which can be fatal.


Recurrences are very frequent since approximately 30 percent of women experience a new UTI episode after the resolution of the initial infection. UTIs are also a major reason for antibiotic treatments and thus strongly contribute to the global issue of antibiotic resistance.

Jean-Philippe Nougayrède and Eric Oswald of Université de Toulouse, and colleagues, analyzed urine samples from 223 patients with community-acquired UTIs at the University Hospital of Toulouse, France. They detected evidence of colibactin synthesis in 55 of the samples examined. In a mouse model of UTI, colibactin-producing bacteria-induced extensive DNA damage in bladder cells. According to the authors, the findings support the idea that UTIs may play a role in bladder cancer.

“Currently the main risk factors for bladder cancers are tobacco and occupational exposure to solvents, which are more frequently investigated than UTIs. However, a large worldwide bladder cancer case-control study recently showed that regular UTIs were epidemiologically associated with an increased risk of urinary bladder cancer,” the researchers wrote.

They further suggested that uropathogenic E.coli should be studied as a possible additional risk factor, particularly in cases of chronic and regular infections, irrespective of whether symptoms are present or not.

The authors conclude, “Our work suggests that there should be a more specific follow-up of patients regularly suffering from urinary tract infections, with a systematic search for colibactin markers in their urine, but also more proactive, by proposing therapeutic approaches aimed at modulating the composition of their intestinal microbiota, which represents the main reservoir of the E. coli bacteria involved in these urinary tract infections.”

Anuradha Varanasi is a freelance science writer. She writes on the intersection of health/medicine, racial disparities, and climate change. She earned an MA in Science