A comparative study of antibiotic susceptibility patterns of biofilm-producing uropathogenic Escherichia coli isolated from clinical samples at a tertiary care hospital in eastern India

Abstract

Urinary tract infections (UTIs) are a prevalent cause of morbidity, with Escherichia coli being a major pathogen. Biofilm production in E. coli significantly impacts antibiotic resistance, complicating UTI management. This study was planned to detect the production of biofilms among uropathogenic E. coli (UPEC) and compare the antibiotic susceptibility patterns of biofilm-producing and nonbiofilm-producing isolates. This study was conducted from December 2022 to June 2024 at a tertiary care hospital in eastern India. Nonintensive care unit patients with UTIs who had not received antibiotics in the past week were included in the study. Biofilm production was assessed using the Tissue Culture Plate Method and Congo red agar (CRA). Antibiotic susceptibility was determined by the Kirby–Bauer disk diffusion method. Of 165 patients, 59% were female, and the majority were aged 41–60 years. No significant differences in biofilm production were found based on age or sex. Strong biofilm producers exhibited significantly higher optical density (OD) values compared to weak and nonbiofilm producers ( P < 0.001). Biofilm-producing strains, particularly strong producers, demonstrated higher resistance rates to antibiotics, including amoxicillin–clavulanate (61% vs. 18%, P < 0.001), gentamicin (68% vs. 15%, P < 0.001), and meropenem (65% vs. 16%, P < 0.001). Nonbiofilm producers generally showed higher sensitivity, highlighting the significant impact of biofilm production on antibiotic resistance in UPEC isolates. The presence of biofilms in E. coli strains significantly contributes to antibiotic resistance. Effective management of UTIs caused by biofilm-producing strains requires an understanding of their resistance mechanisms and the development of targeted therapies.