Diversity of carbapenemase-producing Enterobacterales in England as revealed by whole genome sequencing, January 2014 to June 2016. Enterobacterales

Introduction: Increasing numbers of carbapenemase-producing Enterobacterales (CPE), which can be challenging to treat, have been referred to the national reference laboratory in England since the early 2000s.Results: A total of 2658 non-duplicate CPE were sequenced amongst which three host organisms belonging to diverse sequence types (STs) predominated: Klebsiella pneumoniae (n=1380, 51.9%; 177 STs), Escherichia coli (n=723, 27.2%; 133 STs) and Enterobacter cloacae (n=294, 11.1%; 88 STs). Thirty different carbapenemase gene variants were identified, although blaOXA-48-like (n=1122, 42.2%), blaNDM (n=692, 26%), blaKPC (n=571, 21.5%), blaVIM (n=100, 3.8%) and blaIMP (n=33, 1.2%) predominated. ST/carbapenemase gene pairings represented widely distributed high-risk clones or clusters at a regional or hospital level.Conclusion: CPE referred to the national reference laboratory are diverse, suggesting multiple introductions to England and a role for horizontal transfer of carbapenemase genes in English CPE epidemiology.