Urinary tract infections driven by multi-drug-resistant Escherichia coli in felines: A comprehensive clinical review of resistance mechanisms, pathogenesis, and future therapeutics

Authors and affiliations

Nuzhat Parveen Junejo^*

* Corresponding author: Nuzhat Parveen Junejo

Feline lower urinary tract disease (FLUTD) represents a highly complex and multifaceted clinical challenge in veterinary medicine, characterized by significant morbidity, economic burden on pet owners, and immense diagnostic complexity. Within the broad umbrella of FLUTD, bacterial urinary tract infections (UTIs) account for a substantial subset of cases, heavily disproportionate in older felines and those suffering from systemic comorbidities such as chronic kidney disease, diabetes mellitus, or hyperthyroidism. Decades of microbiological surveillance have unequivocally established Escherichia coli specifically the uropathogenic E. coli (UPEC) pathotype as the predominant etiological agent responsible for the vast majority of feline bacterial cystitis and pyelonephritis cases. Historically considered highly susceptible to empirical first-line antimicrobials, feline UPEC has recently undergone a dramatic evolutionary shift, mirroring the crisis seen in human medicine. The rapid and relentless emergence of multi-drug resistant (MDR) E. coli, particularly strains producing extended-spectrum beta-lactamases (ESBLs) such as the CTX-M family, alongside high-level fluoroquinolone resistance, severely complicates empirical therapy. This escalating resistance is driven by high-risk, intercontinental clonal lineages, most notably Sequence Type 131 (ST131), which has successfully breached the species barrier to transmit bidirectionally between humans and companion animals within shared households. This comprehensive, extended review critically synthesizes the contemporary literature surrounding the molecular pathogenesis of feline UPEC, providing an in-depth analysis of fimbria adhesion, intracellular bacterial community (IBC) formation, and host immune evasion. It extensively delineates the genetic and molecular mechanisms of antimicrobial resistance, focusing on plasmid-mediated horizontal gene transfer and chromosomal mutations in the quinolone resistance-determining regions. Furthermore, this review evaluates the current diagnostic paradigms established by the 2026 International Society for Companion Animal Infectious Diseases (ISCAID) guidelines, distinguishing subclinical bacteriuria from true infection. Finally, we explore the cutting edge of novel and alternative therapeutic interventions, including bacteriophage therapy and virulence inhibitors, establishing a vital framework for aggressive antimicrobial stewardship and the preservation of critical antimicrobial efficacy in companion animal medicine.

Keywords: Feline lower urinary tract disease; feline; pathogenesis; Multi-Drug Resistant; Escherichia coli; biosecurity; disease control

Published:

2026-08-30

Volume and issue:

Volume 1, Issue 1

Pages:

11-17

Article ID:

IJVBS-V1I1P104

Category:

Veterinary Medicine

Junejo NP. Urinary tract infections driven by multi-drug-resistant Escherichia coli in felines: A comprehensive clinical review of resistance mechanisms, pathogenesis, and future therapeutics. Int J Vet Biol Sci. 2026;1(1):11-17.

1. Babacan, O., & İzgür, M. (2020). Detection of virulence factors of Escherichia coli strains isolated from urogenital system infections in dogs and cats. Journal of Turkish Veterinary Medical Society, 2(1), 12-20.
2. Bota, D., Bouvet, J., Bernabeu, S., Ghozzi, R., Doublet, B., & Haenni, M. (2025). Zoonotic potential of uropathogenic Escherichia coli lineages from companion animals. Microorganisms, 13(3), 896.
3. Dorsch, R., von Vopelius-Feldt, C., Wolf, G., Gos, C., Straubinger, R. K., & Hartmann, K. (2015). Feline urinary tract infections: prevalence, risk factors and antimicrobial susceptibility. Journal of Feline Medicine and Surgery, 17(10), 870-878.
4. Hritcu, L. D., Bota, D., & Haenni, M. (2024). Prevalence of Bacterial Urinary Tract Infections in Dogs and Cats with Lower Urinary Tract Diseases and Other Illnesses: A Systematic Review and Meta-Analysis. Animals, 15(23), 3456.
5. Johnson, J. R., Clabots, C., & Kuskowski, M. A. (2008). Sharing of Escherichia coli sequence type ST131 and other multidrug-resistant and urovirulent E. coli strains among dogs and cats within a household. Journal of Clinical Microbiology, 46(11), 3736-3739.
6. Litster, A., Wu, C. C., & Constable, P. D. (2011). Comparison of the efficacy of amoxicillin-clavulanic acid, cefovecin, and enrofloxacin in the treatment of clinical signs of uncomplicated feline lower urinary tract disease. Journal of the American Veterinary Medical Association, 238(11), 1438-1444.
7. Marques, C., Gama, L. T., Belas, A., Bergström, K., Beurlet, S., Briend-Marchal, A., ... & Pomba, C. (2016). European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections. BMC Veterinary Research, 12(1), 213.
8. Moyaert, H., de Jong, A., Simjee, S., Rose, M., & Youala, M. (2024). Antimicrobial Susceptibility of Canine and Feline Urinary Tract Infection Pathogens Isolated from Animals with Clinical Signs in European Veterinary Practices during the Period 2013–2018. Antibiotics, 13(7), 634.
9. Platell, J. L., Cobbold, R. N., Johnson, J. R., Heisig, A., Heisig, P., Clabots, C., ... & Trott, D. J. (2011). Commonality among fluoroquinolone-resistant sequence type ST131 extraintestinal Escherichia coli isolates from humans and companion animals in Australia. Antimicrobial Agents and Chemotherapy, 55(8), 3782-3787.
10. Poirel, L., Madec, J. Y., Lupo, A., Schink, A. K., Kieffer, N., Nordmann, P., & Schwarz, S. (2018). Antimicrobial resistance in Escherichia coli. Microbiology Spectrum, 6(4), 6-4.
11. Saputra, S., Jordan, D., Mitchell, T., Wong, H. S., Abraham, R. J., Kidsley, A., ... & Trott, D. J. (2017).

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