# Urinary tract infection in a cat and cholangiohepatitis in a dog caused by the same strain of CTX-M-14 extended-spectrum beta-lactamase-producing Escherichia coli ST162 in a household: case report

## TL;DR

A single strain of antibiotic-resistant E. coli caused infections in a cat and a dog in the same household, showing how resistant bacteria can spread between pets.

## Contribution

This case report highlights the spread of ESBL-producing E. coli ST162 between pets in a household, emphasizing the risk of antimicrobial resistance transmission.

## Key findings

- Genomic analysis confirmed the same E. coli ST162 strain with CTX-M-14 caused infections in both a cat and a dog.
- The infections occurred months apart but were genetically similar, indicating household transmission.
- This case underscores the potential for antimicrobial-resistant infections to spread among cohabiting animals.

## Abstract

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales can be disseminated within households, including sharing of strains between people and pets, posing a public health risk. This case report demonstrates that household dissemination can also lead to antimicrobial-resistant infections in other pets in the household.

A 14-year-old domestic shorthair cat with a subcutaneous ureteral bypass system was diagnosed with a urinary tract infection caused by Escherichia coli ST162 with CTX-M-14 ESBL. The cat was successfully treated. Seven months later, a 16-year-old mixed-breed dog in the same household was diagnosed with cholangiohepatitis caused by E. coli ST162 with CTX-M-14. Genomic comparison of the feline urine and canine bile isolates showed that they were highly genetically similar, despite months passing between resolution of the cat’s infection and the beginning of the dog’s clinical signs.

Dissemination of ESBL-producing E. coli to other pets, as well as to people, is possible when an animal in the household has an infection. In this case, cohabiting animals both developed clinical infections, highlighting the need for guidance to prevent pet-to-pet spread of antimicrobial-resistant pathogens.