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

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 bla (NDM-1), bla (NDM-5), bla (OXA-181) and bla (OXA-232). The gene bla (NDM-1) was identified in diverse sequence types. The gene bla (NDM-5) was identified almost exclusively in E. coli . The genes bla (OXA-181), bla (OXA-232), and co-carriage of bla (NDM-1) and bla (OXA-232) were found in specific sequence types from certain provinces. Replicon typing revealed the diverse backbones of bla (NDM-1)- and bla (NDM-5)-harbouring plasmids and successful expansion of bla (NDM-1)-harbouring IncN2-type plasmids. Core-genome single-nucleotide polymorphism analysis suggested that bla (OXA-181)-, bla (OXA-232)-, bla (NDM-5)-, and co-carriage of bla (NDM-1) and bla (OXA-232)-associated sub-clonal lineages have recently predominated 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.