Profile of Biofilm Formation and Antimicrobial Susceptibility Patterns of Escherichia coli Isolated from Adult Patients Presenting with Urinary Tract Infections at Ruhengeri Level Two Teaching Hospital, Rwanda

Hyacinthe Mukashema,1 Callixte Yadufashije,1 Aphrodice Tuyishimire,2 Yoranda Imurinde,1 Bruno Rugira Niyonkuru,1 Liliane Muhimpundu,3 Alex Nshimiyimana,1 Celestin Musabyumuremyi,1 Epaphrodite Muhizi,4 Philbert Muhire,4 Thierry Habyarimana1 1Department of Biomedical Laboratory Sciences, INES-Ruhengeri, Musanze, Rwanda; 2Department of Public Health, ICAP at Columbia University, Kigali, Rwanda; 3Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya; 4Department of Internal Medicine, Ruhengeri Level Two Teaching Hospital, Musanze, RwandaCorrespondence: Hyacinthe Mukashema, Department of Biomedical Laboratory Sciences, INES-Ruhengeri, P.O. Box 155, Musanze, Rwanda, Tel +250785007620, Email [email protected]: Urinary tract infections (UTIs) are a public health concern worldwide, with Escherichia coli (E. coli) being the primary cause. Biofilm-forming E. coli increases bacterial resistance to antibiotics, leading to significant morbidity and mortality among patients with UTIs. This study was conducted to determine biofilm formation potential and assess antimicrobial susceptibility patterns of E. coli isolated from adults with suspected UTIs attending Ruhengeri Level Two Teaching Hospital (RLTTH), Rwanda.Methods: A cross-sectional laboratory-based study was conducted between April and June 2025 on 151 adults with suspected UTIs. A questionnaire was used to record sociodemographic characteristics and risk factors contributing to UTIs among the participants. Midstream urine samples were collected, cultured, and biochemically analyzed to identify E. coli in urine samples. Antimicrobial susceptibility profiles were determined using the disc diffusion method. Biofilm production in E. coli isolates was detected using Congo Red Agar (CRA) method.Results: Of 151 adults, 64.2% were female and 35.8% male, and the majority of participants were in the age group of 29– 39 years (34.4%). E. coli accounted for 37/151 (24.5%) isolates, of which 16 (43.2%) were confirmed biofilm producers. High resistance was observed for amoxicillin (100%), trimethoprim-sulfamethoxazole (93.8%), nitrofurantoin (87.5%), ampicillin (87.5%), cefixime (56.2%), gentamycin (50%), and ceftazidime (37.5%). Ciprofloxacin and meropenem were effective. Age was the only risk factor associated with biofilm production by E. coli in the study population (p = 0.000).Conclusion: This study highlights the critical role of E. coli in biofilm production in adults with UTI at RLTTH. A high prevalence of drug resistance was observed among biofilm-producing strains. Intervention strategies, such as frequent biofilm screening, continuous surveillance, and enhanced antimicrobial stewardship programs, are needed.Keywords: UTIs, E. coli, biofilm-producing strains, antimicrobial resistance, Rwanda