What are we eating?. Detection of antibiotic resistance mechanisms in frozen chicken nuggets imported from Brazil

Abstract

The rise of antibiotic resistance is a growing challenge, affecting humans, the environment, and animals. Under the One Health framework, this study investigated resistance mechanisms to critically important antibiotics in frozen chicken nuggets imported from Brazil. Eighty nugget samples were cultured on selective media containing ceftriaxone, ciprofloxacin, or colistin. Isolates were identified using MALDI-TOF, and antibiotic susceptibility was assessed by disk diffusion. Eight samples were also analyzed using shotgun metagenomic sequencing processed through the SqueezeMeta pipeline. Nineteen Enterobacterales resistant mainly to β-lactams and to a lesser extent, to quinolones and aminoglycosides, were identified. Eight Pseudomonas spp. were recovered, including one P. fulva resistant to colistin. Metagenomics revealed predominant Firmicutes, (Bacillaceae, Lactobacillaceae, and Paenibacillaceae) with low γ-Proteobacteria levels. Additionally, we detected resistance genes against several antibiotics. This study highlights the role of imported food in spreading AMR and the value of combining metagenomics with conventional microbiology to strengthen One Health surveillance.