Evolving E. Faecalis Biofilms and UTI Relapse: Does Vaginal Estrogen Matter?

Objectives: Enterococcus faecalis urinary tract infection prevalence peaks in post-menopausal females and these bacteria are known to create biofilms which may reduce treatment efficacy. The role of local vaginal estrogen therapy in susceptibility to E. faecalis infection is unclear. We aim to evaluate differences in antibiotic treatment of E. faecalis UTIs in postmenopausal women using local vaginal estrogen therapy to premenopausal women.

Methods: This is a secondary analysis of a retrospective cohort study of 71 female ambulatory patients. Patients were included if they had a symptomatic Enterococcus faecalis UTI, had a diagnosis of recurrent UTI, and were seen within the gynecologic or urogynecology and reconstructive pelvic surgery practices between 2011 and 2020. Patients were excluded if they had asymptomatic bacteriuria or were pregnant. IRB approval was obtained before the start of data collection. De-identified data was retrieved from the electronic medical record and stored in an institutional-affiliated Redcap database. Data was analyzed utilizing descriptive statistics. A two-sided Fischer’s exact test was run using Prism9 statistical software to compare the outcomes between postmenopausal and premenopausal patients and the prescription of additional rounds of antibiotics. An additional round was defined as a new course of antibiotic therapy for a relapse of the same urinary tract infection and the timing of this additional round was documented.

Results: Within this cohort of 71 patients, 53.4% were postmenopausal and 46.5% were premenopausal. There was no statistically significant difference in the need for additional rounds of antibiotics between postmenopausal and premenopausal patients (11.4% versus 12.9%, p>0.99). 75% and 50% of these additional rounds were prescribed before 2 weeks in the postmenopausal and premenopausal cohorts respectively. When comparing postmenopausal patients not on vaginal estrogen with premenopausal patients, there was no statistically significant difference in the need for additional rounds of antibiotics (10.0% versus 12.9%, p>0.99). There was also no statistically significant difference between postmenopausal women on vaginal estrogen and premenopausal women (13.3% versus 12.9%, p>0.99) and amongst postmenopausal vaginal estrogen users and non-users (13.3.% versus 10.0%, p>0.99).

Conclusions: A small percentage of premenopausal and postmenopausal patients did require additional rounds of antibiotics and the majority of these were prescribed within 2 weeks of the initial prescription. However, there are no statistically significant differences between our estrogen-deficient and estrogenized postmenopausal patients and premenopausal patients in the requirement of additional rounds of antibiotics for E. faecalis with underlying recurrent urinary tract infection.