Biofilm Production by Uropathogens in Postmenopausal Women with Recurrent and Isolated Urinary Tract Infection

Abstract

Objectives: The aims of this study were to assess the in vitro biofilm-producing capabilities of uropathogens grown from a postmenopausal urogynecologic population with isolated and recurrent urinary tract infection (UTI) and to determine whether the biofilm-producing bacterial phenotype was associated with recurrent infection.

Methods: This was an institutional review board-approved cross-sectional analysis within a large academic referral center. Uropathogens were cultured from postmenopausal women with either isolated or recurrent acute UTI and then screened for in vitro biofilm formation using crystal violet microtiter assays. Demographic and clinical variables, including pelvic floor symptoms and surgical history were collected and analyzed. A multivariate model was developed to determine whether recurrent UTI was independently associated with biofilm production.

Results: Eighty-nine women were included: 67.4% White, 25.8% Black, 3.4% Asian, and 1.1% Hispanic with a mean age of 72 ± 10.5 years. Ninety-five uropathogen strains were isolated. Most uropathogens produced biofilm (n = 53, 55.8%). Uropathogens from women with recurrent UTI were significantly more likely to produce biofilm (70%) than uropathogens collected from women with isolated UTI (38.6%, P = 0.0033). Adjusting for age, prior pelvic reconstructive surgery, and body mass index, recurrent UTI bacteria were more likely to produce biofilm, compared with isolated UTI (odds ratio, 5.37; 95% confidence interval, 2.0-14.4; P = 0.001).

Conclusions: In this cohort of postmenopausal urogynecology patients, in vitro biofilm formation was more frequently observed in uropathogens isolated from women with recurrent UTI compared with women with isolated UTI. Further study is needed to assess the role of biofilms in recurrent UTIs in postmenopausal women.