NDM-5-plasmid diversity in multiple international high-risk Escherichia coli clones associated with canine and feline extraintestinal infections.

NDM-5-producing Escherichia coli are the predominant carbapenemase producers of medical and public health importance. The global spread of blaNDM-5-containing plasmids in high-risk E. coli clones has been primarily documented in humans and increasingly reported in animals and the environment. Here, we used whole-genome sequence analysis to describe the genetic diversity of 16 high-risk NDM-5-producing E. coli strains, with a variety of NDM-5 plasmids, isolated from dogs and cats with extraintestinal infections in Thailand between 2017 and 2021. The strains belonged to sequence type (ST) 410 (n = 8), ST354 (n = 3), ST648 (n = 2), ST361 (n = 1), ST617 (n = 1), and ST641 (n = 1). The ST641 strain carried blaNDM-5 on an IncX3 plasmid, while blaNDM-5 was localized on single-replicon or multi-replicon IncF plasmids in other STs. Non-conjugative F1:A1:B49 NDM-5 plasmids were limited to ST410 strains. They contained blaNDM-5 associated with the IS26-bounded complex class 1 integron (Int1) with dfrA17-aadA5-qacEΔ1-sul1 cassette array that shared similarities to nearly identical structures with the plasmids of ST410 strains from humans in Thailand and Myanmar. Conjugative IncFII (F2:A-:B-) NDM-5 plasmids containing Int1 with dfrA12-aadA2-qacEΔ1-sul1 cassette array were present in ST354 and ST648, and heterogeneous plasmid STs of conjugative multi-replicon IncF NDM-5 plasmids were found in ST361, ST410, ST617, and ST648. The blaNDM-5 elements mobilized by IS26 were shared among various IncF plasmids in high-risk E. coli clones but were conserved within the endemic E. coli ST410, representing the predominant lineage in Southeast Asian countries. Dogs and cats can develop infections with NDM-5-producing E. coli, posing the risk of further disseminating carbapenemase in veterinary settings and the community. This emphasizes the need to implement infection control and antimicrobial resistance surveillance programs in veterinary settings.