Targeting vaginal bacteria to prevent recurrent urinary tract infections

There may be a microbial connection between the vagina and bladder in postmenopausal women suffering from recurrent urinary tract infections. A team of urologists from Okayama University, Japan, have detected a genetic similarity in the uropathogenic E. coli (UPEC) bacteria isolated from the urine and vagina of women with recurrent cystitis (RC). Their study was published in the Journal of Infection and Chemotherapy.This bacterium, known to cause RC, can migrate from the vagina to the bladder via the intestinal tract, eventually invading vaginal cells over the long term. “Therefore, the vagina may be the reservoir that facilitates CR via the mechanism of UPEC migration from the vagina to the bladder,” explained the researchers, who set out to decipher the genotypic characteristics of vaginal and urinary UPEC by comparing their genotypic homology and phenotypic antimicrobial susceptibility. Between 2014 and 2019, they analyzed the bacteria present in the vagina and urine at the onset of cystitis of seven postmenopausal patients with recurrent urinary tract infections. Their median age was 66 and they had five episodes of cystitis per year. A total of 14 strains were isolated.Study co-author Dr. Takanori Sekito’s team defines chronic cystitis according to current guidelines:at least three episodes of acute bacterial cystitis within one year requiring antibiotic therapy orat least two episodes of acute bacterial cystitis within six months requiring antibiotic therapyPerforming pulsed-field gel electrophoresis, urologists found clonal similarity ranging from 89.5% to 100% per patient, with four strains 100% identical. The urinary and vaginal UPECs “are identical in terms of genotypic homology and phenotypic antimicrobial susceptibility,” the authors wrote.In addition, a double-disk synergy test confirmed the presence of extended-spectrum beta-lactamase-producing bacteria produced by E. coli. The results suggest that the vagina acts as a reservoir contributing to recurrence, since UPEC has infiltrated the vaginal epithelium after adhesion and internalizes into the cells.Lactobacillus crispatus, a promising solution"When UPECs invade and aggregate in urinary tract cells, they are known to form intracellular bacterial communities resembling biofilms,” the authors said. "This colony formation allows UPEC to evade various antimicrobial agents and the immune system, and UPEC infections are characterized as refractory and prone to recurrence.”The results emphasize the importance of vagina-targeted approaches, such as using Lactobacillus crispatus-based vaginal suppositories, for example. This is a promising strategy according to the researchers as addressing both vaginal and urinary UPEC is essential in the treatment of recurrent cystitis. While uncomplicated cystitis requires a short course of antimicrobial therapy, ranging from one to five days, there is little evidence on the types and durations of antimicrobial agents used to treat CR.This article was translated from its original French and first appeared on our sister site Profession Santé.

Targeting vaginal bacteria to prevent recurrent urinary tract infections

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