Nationwide surveillance in Thailand revealed genotype-dependent dissemination of carbapenem-resistant Enterobacterales

Abstract

Carbapenem-resistant Enterobacterales (CRE) are a serious public health threat because of their rapid dissemination. To determine the epidemiological and genetic characteristics of CRE infections in Thailand, we performed whole-genome sequencing of 577 carbapenem-resistant Klebsiella pneumoniae isolates and 170 carbapenem-resistant Escherichia coli isolates from hospitals across the nation. The four most prevalent carbapenemase genes harboured by these bacteria were blaNDM-1, blaNDM-5, blaOXA-181 and blaOXA-232. The gene blaNDM-1 was identified in diverse sequence types. The gene blaNDM-5 was identified almost exclu-sively in E. coli. The genes blaOXA-181, blaOXA-232, and co-carriage of blaNDM-1 and blaOXA-232 were found in specific sequence types from certain provinces. Replicon typing revealed the diverse backbones of blaNDM-1-and blaNDM-5-harbouring plasmids and successful expansion of blaNDM-1-harbouring IncN2-type plasmids. Core-genome single-nucleotide polymorphism analysis suggested that blaOXA-181-, blaOXA-232-, blaNDM-5-, and co-carriage of blaNDM-1 and blaOXA-232-associated sub-clonal lineages have recently predomi-nated in the provinces from where these isolates were isolated. Thus, we demonstrate genotype-dependent dissemination of CRE in Thailand, which is helpful for establishing infection-control strategies in CRE-endemic areas.