Abstract
Background: Antimicrobial resistance (AMR) in Escherichia coli poses a significant global health threat, with companion animals potentially serving as reservoirs for resistant strains. In Uganda, data on AMR in E. coli from companion animals and humans are limited, particularly in urban settings. This study aimed to characterize and compare AMR patterns in E. coli isolates from companion animals and humans in Kampala, Uganda.Methods: A cross-sectional study was conducted from January to June 2023. A total of 200 E. coli isolates were collected: 100 from companion animals (dogs and cats) presenting at veterinary clinics and 100 from human outpatients at healthcare facilities in Kampala. Antimicrobial susceptibility testing was performed using the disk diffusion method against 12 antibiotics. Statistical analyses included chi-square tests and logistic regression to identify factors associated with multidrug resistance (MDR).Results: Overall, 78% of isolates were resistant to at least one antibiotic, and 52% were MDR. Resistance was highest for tetracycline (65%), ampicillin (58%), and sulfamethoxazole-trimethoprim (47%). No significant difference in overall resistance was observed between animal and human isolates (p=0.21), but MDR was significantly higher in animal isolates (61% vs. 43%, p=0.01). Resistance to ciprofloxacin and third-generation cephalosporins was notable at 18% and 12%, respectively.Conclusions: High levels of AMR, including MDR, were found in E. coli from both companion animals and humans in urban Uganda, with animal isolates showing a higher MDR prevalence. These findings underscore the need for a One Health approach to AMR surveillance and antimicrobial stewardship in both veterinary and human medicine.