In silico Evolution and Comparative Genomic Analysis of IncX3 Plasmids Isolated From China Over Ten Years

IncX3 plasmids are correlated with the dissemination and acquisition of carbapenem resistance in Enterobacteriaceae and have been prevalent in China over the last 10 years. Since the distribution characteristics of IncX3 plasmids across China as well as their evolutionary traits for 10 years remain unclear, here we conducted a retrospective literature review and in silico comparative analysis of IncX3 plasmids in publicly available IncX3 plasmid genomes. IncX3 plasmids distributed in 17 provinces or cities were extracted for analysis, which tend to be specifically associated with hospital-isolated Escherichia coli ST410 from phylogroup A. Although the backbones of IncX3 plasmids have remained highly conservative over the last 10 years, the blaNDM resistance genetic contexts on these plasmids could fall into five subtypes, among which AR_N1_I has been identified in Enterobacter cloacae174 chromosome and AR_N5_I was simultaneously located on IncF and IncA/C plasmids. This suggests that the blaNDM resistance gene environment can spread between different plasmids, between different bacterial genera, or between strains and plasmids, highlighting that it is imperative to adopt more stringent infection control measures targeting IncX3 plasmid spread.