Bladder-resident bacteria associated with increased risk of recurrence after electrofulguration in women with antibiotic-recalcitrant urinary tract infection

Background. Antibiotic-recalcitrant recurrent urinary tract infection (rUTI) is has become increasingly observed in postmenopausal women. Therefore, when standard antibiotic therapies have failed, some elect electrofulguration (EF) of areas of chronic cystitis when detected on office cystoscopy. EF is thought to remove tissue-resident bacteria that have been previously detected in the bladder walls of postmenopausal women with rUTI. We hypothesized that increased bladder bacterial burden may be associated with incomplete rUTI resolution following EF. Methods. Following IRB approval, bladder biopsies were obtained from 34 consenting menopausal women electing EF for the advanced management of rUTI. 16S rRNA FISH was performed using both universal and Escherichia probes and tissue-resident bacterial load was quantified. Time to UTI relapse after EF was recorded during a six-month follow-up period and the association of bladder bacterial burden and clinical covariates with UTI relapse was assessed. Results. We observed bladder-resident Escherichia in 52% of all participants and in 92% of participants with recent E. coli UTI. Time-to-relapse analysis revealed that women with high bladder bacterial burden as detected by the universal probe had a significantly (p=0.035) higher risk of UTI within six months of EF (HR=3.15, 95% CI: 1.09-9.11). Interestingly, bladder-resident Escherichia was not significantly associated (p=0.26) with a higher risk of UTI relapse (HR= 2.14, 95% CI: 0.58-7.90). Conclusions. We observed that total bladder bacterial burden was associated with a 3.1x increased risk of rUTI relapse within six months. Continued analysis of the relationship between bladder bacterial burden and rUTI outcomes may provide insight into the management of these challenging patients.