Molecular Epidemiology and Multilevel Drug Resistance Mechanisms of Escherichia coli in the Context of One Health: A Comprehensive Narrative Review.

Escherichia coli (E. coli) is an important pathogen responsible for foodborne disease outbreaks and can be transmitted through the food chain via the fecal-oral route, causing both intestinal and extraintestinal infections in warm-blooded animals. Against the backdrop of improper use of antibiotics in medicine, agriculture, and animal husbandry, together with the adaptive evolutionary capacity of E. coli, the increasing detection rate of multidrug-resistant E. coli and the shifting of dominant clones among regions have posed a great challenge to the treatment and control of infections. Against this background, this comprehensive narrative review takes the molecular epidemiological characteristics of E. coli as an entry point to systematically summarize its biological features and epidemiological patterns and then explains the mechanisms of antibiotic resistance from the molecular level, including intrinsic resistance conferred by its inherent structural features, acquired resistance (acquisition of drug resistance genes, alteration of drug targets, production of target protection proteins, enzymatic modification and inactivation of antibiotics, changes in cell membrane permeability, and upregulation of active efflux pump systems) and biofilm-mediated adaptive resistance. Finally, this review summarizes current antibiotic treatment strategies and emerging therapeutic approaches for E. coli infections. Within a One Health framework, this review highlights the resistance characteristics and transmission dynamics of E. coli to inform prevention strategies and antimicrobial development.