Biofilm Associated Uropathogenic Escherichia coli from Catheterised Patients at a Nigerian Hospital

Catheter-associated urinary tract infections (CAUTIs) pose a significant health risk in healthcare facilities, accounting for 40% of all hospital-acquired infections and 80% of healthcare-acquired urinary tract infections. These infections are often associated with biofilm formation, which can lead to recurrent or persistent infections due to antimicrobial resistance. In this study, urine samples from 230 catheterised patients, mostly males (91.3%), were analysed to investigate the prevalence of biofilm-forming uropathogenic E. coli (UPEC) and their correlation with antibiotic resistance. Standard microbiological methods and the Analytical Profile Index (API) 20E were used to isolate and identify UPEC, while the microtiter plate method was used to screen UPEC for their ability to form biofilms under static and dynamic conditions. An antimicrobial susceptibility test was also performed using a modified Kirby-Bauer disc diffusion method. The results of the study showed that UPEC was present in 21.7% of catheterized urine samples, with patients with long-term catheterization accounting for 96% of these isolates. Among these isolates, 84% and 86% were found to form biofilms under static and dynamic conditions, respectively, with all strong biofilm-forming isolates being extensively drug-resistant. The study also found a significant correlation between biofilm formation and resistance to most antibiotics tested, including Augmentin, Ceftazidime, Ceftriaxone, Gentamicin, and Ciprofloxacin (p-value < 0.05). However, Imipenem and nitrofurantoin showed no significant correlation with biofilm formation (p-value > 0.05). Given these findings, it is recommended that routine tests include biofilm detection and antimicrobial susceptibility assessments to guide the choice of a suitable antibiotic treatment, which is essential for effective management.