Multi-species blaNDM outbreak in multiple tertiary and a primary healthcare facility in Merseyside, UK, driven by a combination of multi-species plasmids and small clonal outbreaks.

This study captures an outbreak of blaNDM positive Enterobacterales in Merseyside hospitals and highlights the complex epidemiology of spread mediated both by expansion of successful lineages (K. pneumoniae ST101) and plasmids. A dominant IncHI2/IncHI2A plasmid that has disseminated blaNDM-1 across different species and subsequently led to small clonal outbreaks within-hospitals. This highlights the cross-species movement of AMR elements as an important factor in AMR dissemination, and the importance of both species-specific surveillance to monitor local outbreaks, but also species-agnostic surveillance to include plasmids spreading across species.