Enumeration, antimicrobial resistance and genomic characterization of extended-spectrum β-lactamases producing Escherichia coli from supermarket chicken meat in the United Arab Emirates.

The occurrence and counts of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in retail chicken sold in the United Arab Emirates (UAE) were investigated in this study. Results indicated that 79.68 % of chicken carcasses (251/315) sampled from UAE supermarkets harbored ESBL-producing E. coli. About half (51.75 % [163/315]) of the tested samples had an ESBL-producing E. coli count range between ≥3 log and < 5 log CFU/g. The antimicrobial resistance profiles of a subset of 100 isolates showed high rates of non-susceptibility to clinically significant antibiotics, particularly ciprofloxacin (80 %) and cefepime (46 %). Moreover, 7 % of the isolates exhibited resistance to colistin, with PCR-based screening revealing the presence of the mcr-1 gene in all colistin-resistant isolates. Multiplex PCR screening identified bla and bla genes as the most frequently presented genes among the phenotypically confirmed ESBL-producing E. coli. Further whole-genome sequencing and bioinformatic analysis of 27 ESBL-producing E. coli isolates showed that the gene family bla group 1 was the most prevalent, notably CTX-M-55 (55.55 % [15/27]), followed by CTX-M-15 (22.22 % [6/27]). The most common sequence types (STs) were ST359 and ST1011, with three evident clusters identified based on phylogenomic analysis, aligned with isolates from specific production companies. Analysis of plasmid incompatibility types revealed IncFIB, IncFII, Incl2, and IncX1 as the most commonly featured plasmids. The findings of this study indicate a noticeable prevalence and high counts of ESBL-producing E. coli in chicken sampled from supermarkets in the UAE. The high rates of antimicrobial resistance to clinically important antibiotics highlight the potential public health risk associated with consuming chicken contaminated with ESBL-producing E. coli. Overall, this study emphasizes the importance of continued antimicrobial resistance monitoring in the UAE food chain and calls for further exposure risk assessment of the consumption of ESBL-producing E. coli via chicken meat.