Genomic profiling of extended-spectrum β-lactamase-producing Escherichia coli from Pets in the United Arab Emirates: Unveiling colistin resistance mediated by mcr-1.1 and its probable transmission from chicken meat – A One Health perspective

Background: The United Arab Emirates (UAE) has witnessed rapid urbanization and a surge in pet ownership, sparking concerns about the possible transfer of antimicrobial resistance (AMR) from pets to humans and the environment. This study delves into the whole-genome sequencing analysis of ESBL-producing E. coli strains from healthy cats and dogs in the UAE, which exhibit multidrug resistance (MDR). Additionally, it provides a genomic exploration of the mobile colistin resistance gene mcr-1.1, marking the first instance of its detection in Middle Eastern pets. Methods: We investigate 17 ESBL-producing E. coli strains from healthy UAE pets using WGS and bioinformatics analysis to identify genes encoding virulence factors, assign diverse typing schemes to the isolates, and scrutinize the presence of AMR genes. Furthermore, we characterized plasmid contigs housing the mcr-1.1 gene and conducted phylogenomic analysis to evaluate their relatedness to previously identified UAE isolates. Results: Our study unveiled a variety of virulence factor-encoding genes within the isolates, with fimH emerging as the most prevalent. Regarding β-lactamase resistance genes, the blaCTX group 1 gene family predominated, with CTX-M-15 found in 52.9% (9/17) of the isolates, followed by CTX-M-55 in 29.4% (5/17). These isolates were categorized into multiple sequence types (STs), with the epidemic ST131 being the most frequent. The presence of the mcr-1.1 gene, linked to colistin resistance, was confirmed in two isolates. These isolates belonged to ST1011 and displayed distinct profiles of β-lactamase resistance genes. Phylogenomic analysis revealed close connections between the isolates and those from chicken meat in the UAE. Conclusion: Our study underscores the presence of MDR ESBL-producing E. coli in UAE pets. The identification of mcr-1.1-carrying isolates warrants the urgency of comprehensive AMR surveillance and highlights the role of companion animals in AMR epidemiology. These findings underscore the significance of adopting a One Health approach to mitigate AMR transmission risks effectively.