Integral genomic description of blaNDM-5-harbouring plasmids recovered from Enterobacterales in Argentina.

Objective: To characterise four bla_NDM-5-harbouring plasmids recovered in Enterobacterales isolated in Argentina.

Methods: DNA was sequenced by Illumina and Oxford Nanopore technologies, assembled using Unicycler, analysed using PlasmidFinder, MOB-Typer, IslandViewer4 and Resfinder, and visualised by Proksee and Clinker. bla_NDM-5-harbouring plasmids were compared with deposited similar ones using PLSDB.

Results: two plasmids belonged to incompatibility group IncFII where bla_NDM-5 was located in a previously described genetic context, immersed in an antimicrobial resistance island (ARI). Local IncFII plasmids displayed high similarity (≥ 90% shared hashes (sh)) with four deposited in PLSDB. The other two local plasmids belonged to the multi-replicon group IncFIB-HI1B, harbouring bla_NDM-5 in a novel variant of the genetic context. Both multi-replicon plasmids, presented two ARI, one containing bla_NDM-5 in addition to other ARM; and the second ARI carrying bla_CTX-M-15 and a class 1 integron. Plasmids deposited in PLSDB showed low similarity to local multi-replicon plasmids. The most similar plasmids (n:5) displayed less than 60% sh showing the same Inc groups but lacking ARM.

Conclusion: This study broadens the limited understanding of bla_NDM-5-harbouring plasmids in Latin America. Furthermore, it represents the first description of bla_NDM-5 in a novel variant of the common genetic platform and its location in multi-replicon IncFIB-IncHI1B plasmids, which were not previously associated with any antimicrobial resistance marker (ARM).