Multidrug resistance of Escherichia coli isolated from the urinary bladder of dogs and cats with suspected urinary tract infections

Introduction and Objective. Escherichia coli is one of the most common bacteria isolated from urine samples collected from dogs and cats with urinary tract infection (UTI). Uncomplicated UTIs in dogs and cats can be treated with short courses of first-line antimicrobial drugs, e.g. amoxicillin, amoxicillin with clavulanic acid, or trimethoprim/sulfonamide. Recurrent or complicated UTIs often require long-term treatment with broad-spectrum antibiotics. However, the choice of drug should be based on antimicrobial susceptibility. Materials and method. Between March – September 2022, E. coli isolates cultured from the urine of 66 dogs and 41 cats with UTI symptoms were tested for antimicrobial resistance by using Minimum Inhibitory Concentration (MIC). Antimicrobial susceptibility was tested for ampicillin, ampicillin/sulbactam, cefazolin, cefuroxime, aztreonam, gentamycin, amikacin, colistin, trimethoprim/sulfamethoxazole, ciprofloxacin, chloramphenicol and tetracycline. Results. The highest prevalence of resistance was documented for ampicillin (68% in dogs, 100% in cats) and ampicillin with sulbactam (59% in dogs, 54% in cats). The most common antimicrobial resistance patterns of E. coli were ampicillin alone (12 isolates, 29.3% in cats) and beta-lactams, including aztreonam (14 isolates, 21.2% in dogs). Conclusions. High resistance to aztreonam (61% and 32% of isolates from dogs and cats, respectively), other beta-lactams, and fluoroquinolones should cause be alarm due to zoonotic potential and cross-transmission of antimicrobial-resistant microorganisms between animals and humans.