Emergence of almost identical F36:A-:B32 plasmids carrying bla_NDM-5 and qepA in Escherichia coli from both Pakistan and Canada

The New Delhi Metallo-β-lactamase (NDM) producing Enterobacteriaceae is spreading worldwide. Although the bla_NDM gene has been identified in animal associated Enterobacteriaceae isolates in many countries, little is known about its occurrence in animal products in Pakistan.

In this study, 13 Escherichia coli isolates were collected from chicken meat samples in Pakistan. Two isolates, 15978 and C4109, exhibited reduced susceptibility (MIC ≥1 μg/mL) to imipenem, and carried bla_NDM-5 and bla_NDM-7 gene, respectively. Whole-genome sequencing and Oxford Nanopore MinION sequencing revealed that 15978 and C4109 belonged to ST156 and ST167, respectively. bla_NDM-7 was carried by an IncX3 plasmid that has disseminated worldwide, whereas bla_NDM-5 was located on an F36: A-: B32 plasmid, which shared high identity with two plasmids carried by E. coli isolates from other countries (one from a patient in Canada).

To the best of our knowledge, this is the first report characterizing bla_NDM-carrying plasmids from chicken meat samples in Pakistan. The dissemination of almost identical bla_NDM-5-bearing F36:A-:B32 and bla_NDM-7-bearing IncX3 plasmids in different countries highlights the importance of international trade and travel in the spread of antimicrobial resistance strains and plasmids worldwide.