ESBL-Producing Escherichia coli: The Role of Plasmids in Antibiotic Resistance

Abstract

Background: Plasmids are the major route of the dissemination of resistance genes between species, sectors and geographical locations, and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are a critical health threat globally. Objective: Based on recent knowledge, this review intends to bring together the molecular epidemiology, plasmid biology, horizontal gene transfer mechanisms and therapeutic approaches in ESBL-producing E. coli, with a focus on the transmission dynamics in the realm of One Health. Methods: We searched the literature in PubMed, Scopus, and Web of Science from 2015 to 2026 using the keywords, "ESBL," "E. coli," "plasmids," "antibiotic resistance," "horizontal gene transfer," and "One Health”. Articles were selected based on their relevance to understanding the nature of plasmid mediated resistance, epidemiology, and strategies for interventions. Results: ESBL-encoding plasmids vary in different species and contain a range of resistance determinants, such as blaCTX-M, blaTEM, blaSHV genes, which are frequently found together with aminoglycoside, quinolone and colistin resistance genes, with prevalence of IncF, IncI, IncN or IncHI2 plasmid types. The pandemic ST131 clone shows good plasmid-host adaptation that has different dominant subclades in different regions. Plasmids are very flexible in terms of the presence of mobile genetic elements (ISEcp1, IS26) that allow the capture and dissemination of resistance genes. Multidrug resistance and virulence determinants converged on epidemic plasmids and resulted in hypervirulent multidrug resistant strains. Conclusions: A systems biology approach to better understand plasmid biology, together with new technologies such as long-read sequencing and artificial intelligence, and the need to support the One Health approach, are all crucial to reducing the threat of ESBL-producing E. coli. There are potential treatment options that are directed towards resistance plasmids, but they need to be developed and verified.