Temporal shifts in the predominant carbapenemase gene types among carbapenemase-producing isolated in Bangkok, Thailand, during 2013-2016.

Carbapenemase-producing Enterobacteriaceae (CPE) have emerged as a global threat to public health and clinical practice. In Thailand, reports describing CPEs carrying and -like genes have been increasing recently; however, data on detailed plasmid analysis and temporal shift of sequence type and carbapenemase type are limited. In this study, we analysed whole-genome sequencing (WGS) data of clinically isolated carbapenemase-producing (CPKP) to reveal the molecular epidemiology of CPKP in a tertiary-care hospital in Bangkok, Thailand. Seventy-seven non-duplicated CPKP isolates collected during 2013-2016 were examined for their drug-resistance genes, sequence types and phylogenetic relationships. All the tested isolates possessed carbapenemase gene(s), and the major type of carbapenemase gene in 2014-2015 was , whereas isolates in 2016 harboured more than . Other carbapenemase gene variants, such as , , , and were detected in some CPKP isolates. Furthermore, this study revealed that CPKP co-harbouring two genes, and or , emerged during this period. Notably, such isolates co-carrying the two carbapenemase genes emerged in three different sequence types, even in a single hospital, and then spread clonally. The WGS of CPKP revealed a temporal shift of the predominant carbapenemase genes from to along with a variation in other carbapenemase gene types within a span of 4 years. Our findings suggest that a substantial change in CPE types occurred in Thailand and potentially in Southeast Asian countries.