Rapid detection and characterization of *tet*(X4)-positive *Escherichia coli* strains with nanopore sequencing

Novel antimicrobial resistance genes harboured by pathogens pose a great public health concern, as exemplified by the emergence of bla_NDM-1 and mcr-1 over the past decade. Recently, two novel plasmid-mediated tigecycline resistance genes, tet(X3) and tet(X4), were identified in Enterobacteriaceae and Acinetobacter in two studies, which has inevitably caused worldwide concern.

Following the recent studies reporting plasmid-mediated tet(X) genes, we utilized nanopore sequencing to characterize three tet(X4)-positive Escherichia coli strains of pork origin and highlighted the feasibility of nanopore sequencing in investigating and tracking emerging novel resistance genes.