Genomic Comparison Reveals Natural Occurrence of Clinically Relevant Multidrug-Resistant Extended-Spectrum-β-Lactamase-Producing Escherichia coli Strains

Multidrug-resistant (MDR)Escherichia coli isolates pose global threats to public health due to the decreasing availability of treatment options. To better understand the characteristics of MDRE. coli isolated from food-producing animals with no antibiotic exposure, we employed genomic comparison, high-resolution phylogenetics, and functional characterization. Our findings highlight the potential capacity of MDRE. coli to cause severe disease and suggest that these strains are widespread intercontinentally. This study underlines the occurrence of MDRE. coli in food-producing animals raised without antibiotic use, which has alarming, critical ramifications within animal and human medical practice.