IncN-R plasmid co-integration contributing to extensive drug resistance in Escherichia coli isolated from a canine prostatic abscess.

The emergence of multidrug-resistant (MDR) plasmids poses a significant global public health threat. This study characterized a novel multi-replicon IncN-R MDR plasmid pCUVET19-1426.1, harboring blaCTX-M-55 and 12 additional antimicrobial resistance genes (ARGs) in a newly identified Escherichia coli sequence type 13037, isolated from a canine prostatic abscess. Using antimicrobial resistance (AMR) profiling and genomic analysis, we elucidated the characteristics, evolution, and transferability of plasmid pCUVET19-1426.1, which contributed to the extensively drug-resistant phenotype of the bacterial strain. The plasmid is genetically related to IncN plasmids found in Enterobacterales from humans and animals in Thailand, suggesting plasmid circulation and evolution. Multiple IS26 elements enhanced the plasmid plasticity for co-integration and acquisition of ARGs, underscoring its significant clinical and public health impact. Our findings emphasize the importance of genomic insights in understanding plasmid evolution and its role in AMR development in E. coli, causing opportunistic infections.IMPORTANCEThis study highlights the significance of plasmid evolution to generate a new multi-replicon IncN-R plasmid encoding an extended-spectrum β-lactamase and multidrug resistance (MDR) in a new Escherichia coli sequence type 13037 from a canine prostatic abscess. We provide insights into the genetic mechanisms facilitating the spread and persistence of resistance genes, driving the emergence of an extensively drug-resistant phenotype. The presence of an MDR plasmid in the clinical E. coli isolate critically limited antimicrobial options for extraintestinal infections in small animal veterinary medicine. The plasmid's genetic relatedness underscores the interconnectedness of human and animal health, emphasizing the importance of a One Health approach. These findings emphasize the need to enhance genomic surveillance to monitor the evolution of bacterial plasmids and their role in antimicrobial resistance development in both human and animal health.