Abstract: 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.
Keywords: plasmid, animal food, carbapenemase, bla _NDM