First national study on genomic profiling of Escherichia coli in United Arab Emirates (UAE) aquatic environments shows diverse Quinolone and Cephalosporin resistance

Antimicrobial resistance (AMR) is a serious threat to human, animal and plant health, and over recent years the role of the aquatic environment as a hotspot and dissemination route for resistant bacteria has been increasingly recognised. The United Arab Emirates (UAE) has identified AMR as a critical area of concern; however, limited studies have been conducted regarding the presence of AMR in aquatic environments in the region. This study addresses this gap by conducting a national surveillance to better understand the prevalence of aquatic AMR. We investigated the phenotypic and genotypic resistances in Escherichia coli (E. coli) isolates (n= 256) from sewage impacted and unimpacted coastal waters and artificial lakes across the UAE. Multidrug resistance was observed in 34.2% of isolates, with 22.7% exhibiting resistance to 3^rd and 4^th generation cephalosporins, cefotaxime and ceftazidime, including 16.6% displaying an extended-spectrum β-lactamase (ESBL) phenotype. Resistance to fluoroquinolones, macrolides, and carbapenems was also detected. Whole-genome sequencing (n=92) revealed a high prevalence of the fimH virulence gene, as well as conjugative plasmids (IncF, IncA/C and IncY) carrying resistance determinants. Notably, qnrS1 and bla_CTX-M-15 resistance genes were identified in 39% of sequenced isolates, while the bla_NDM-5 gene was detected for the first time in a single isolate. These findings underscore the need for harmonised AMR surveillance and a regional monitoring framework to assess the environmental dissemination of AMR bacteria in a One Health context.