Whole genome analysis identified a cefotaxime-resistant Empedobacter brevis GBW-1 isolate from ground beef encoding a novel metallo-beta-lactamase variant, blaEBR-6

While investigating foodstuffs for ESBL-producingAeromonasspecies on ampicillin dextrin agar with vancomycin and cefotaxime, a multidrug-resistantEmpedobacter brevisstrain GBW-1 was identified from ground beef. Phylogenetic analysis supports the interconnectedness of environment, humans and food driving this species evolutionary development. Antimicrobial susceptibility testing demonstrated resistance to gentamicin, carbapenems and third-generation cephalosporins. Whole genome sequencing of this strain detected a 3.74 Mb genome with 32.8% GC content containing 3,780 coding genes. Among these genes, at least three known antimicrobial resistance (AMR) genes were identified withqacG, vanTgene within thevanGcluster, and a novel variant of the metallo-β-lactamasebla _EBR-6. This novel homologue, EBR-6, was compared against previously known EBR variants and was found to be closest to EBR-3 with an 84.98% amino acid identity match. Docking software predicted these mutations vary the binding to meropenem. Furthermore, nearly 100 annotated regions associated with mobile genetic elements, including the presence of three, separatetraoperons were identified on the genome. Together, these findings implicate the importance of horizontal gene transfer in the acquisition of AMR among the emerging pathogenEmpedobacter brevisand further stress its One Health nature.