Role of Horizontal Transfer in Antibiotic Resistance Evolution: Addressing the controversial role of E. coli strains from food sources in disease, the Camps lab has employed advanced genomics techniques to shed light on this issue. Our research has revealed that while food strains are rarely found in clinical infections, we act as vital reservoirs for plasmids carrying antibiotic resistance and virulence genes. By identifying specific replicons associated with distinct gene cargo, we have uncovered functional plasmid specialization. Moreover, our investigations have uncovered replicons capable of shuttling between food and clinical environments, emphasizing our role in horizontal gene transfer. Furthermore, our ongoing work examines the constrained evolutionary landscape of plasmid-borne resistance genes in clinical E. coli strains, assessing the relative contributions of genetic linkage and selective pressure.