Reexamining the Association of AmpC Variants with Enterobacter Species in the Context of Updated Taxonomy.

We performed whole-genome sequencing for 17 Enterobacter clinical strains and analyzed all available Enterobacter genomes and those of its closely related genera (n = 3,389) from NCBI. The exact origins of plasmid-borne blaCMH and blaMIR genes are Enterobacter cloacae and Enterobacter roggenkampii, respectively, while plasmid-borne blaACT genes originated from multiple other Enterobacter species, including Enterobacter xiangfangensis, Enterobacter hoffmannii, Enterobacter asburiae, Enterobacter ludwigii, and Enterobacter kobei. The genus Enterobacter represents a large reservoir of plasmid-borne AmpC β-lactamase.