Phylogenomic investigation of IncI1-I plasmids harboring blaCMY-2 and blaSHV-12 in salmonella enterica and Escherichia coli in multiple countries

The objective of this study was to elucidate the genetic and evolutionary relatedness of blaCMY-2- and blaSHV-12-carrying IncI1-I plasmids. Phylogenomic analysis based on core genome alignments and gene presence/absence was performed for different IncI1-I sequence types (STs). Most IncI1-I/ST12 and IncI1-I/ ST231 plasmids had near-identical core genomes. The data suggest that widely occurring blaCMY-2-carrying IncI1-I/ST12 plasmids originate from a common ancestor. In contrast, blaSHV-12 was inserted independently into different IncI1-I/ST231-related plasmids