July 9, 2020

Recurrent UTIs linked to hidden reservoir

Bacterial invasion of vaginal cells sets up a protective niche and a reservoir for recurrent urinary tract infections, Vanderbilt researchers demonstrated.

Urinary tract infections (UTIs) frequently recur due to bacteria constructing safe havens within the host. While infection is frequently caused by uropathogenic Escherichia coli that originates in the gut, little is known regarding vaginal colonization leading to recurrent UTIs.

John Brannon, PhD, Maria Hadjifrangiskou, PhD, and colleagues demonstrated that UTI-causing bacteria not only invaded vaginal cells to create a reservoir and escape antibiotic assault, but also traversed from the reproductive tract to the urinary system.

The team also found that vaginal cell invasion occurs by a separate mechanism than bladder infection, requiring a different signaling pathway to remodel the host cell for bacterial uptake.

These findings, reported in Nature Communications, elucidate a new stage in UTI progression with a unique mode of vaginal cell invasion to create a protective niche for the bacteria and a reservoir for reestablishing infection. The vaginal niche constitutes a potential new avenue exploited by E. coli to cause recurrent urinary tract infection.

This research was supported by National Institutes of Health grants AI107052, DK123967, DK103910, AI112541 and GM007569, and by the March of Dimes.