Bacterial toxin is found in patients with urinary tract infections

PLOS

IMAGE:  During a urinary tract infection, uropathogenic Escherichia coli (their DNA is marked in red) producing the genotoxin colibactin and forming bacterial communities within the superficial cells of the bladder (the nucleus of the cells is marked in blue, their cellular sugar content is marked in green), here six hours after a replicated infection in mice.

CREDIT: CHAGNEAU CV, ET AL. (2021) PLOS PATHOGENS

A DNA-damaging bacterial toxin called colibactin is produced in patients with urinary tract infections (UTIs), according to a study published February 25th in the open-access journal PLOS Pathogens by Jean-Philippe Nougayrède and Eric Oswald of Université de Toulouse, and colleagues.

UTIs are among the most common bacterial infections, affecting approximately 150 million individuals each year. UTIs occur most frequently in women, with more than 60% of females diagnosed with a UTI during their lifetime. In addition to their consequences in terms of illness, mortality, and economic losses, UTIs are also a major reason for antibiotic treatments and thus strongly contribute to the global issue of antibiotic resistance. Uropathogenic E. coli (UPEC) cause approximately 80% of all UTIs. In the new study, the researchers show that colibactin, which is suspected of being involved in cancer, is produced in UPEC-infected patients with UTIs.

The researchers analyzed urine samples from 223 patients with community-acquired UTIs, and detected evidence of colibactin synthesis in 55 of the samples examined. Moreover, UPEC strains isolated from these patients produced colibactin. 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.

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.”