Population structure of CRE isolates. Number and proportion of CRE isolates harboring bla_KPC (n = 460) that belonged to each (A) bacterial species and (B) ST. Doubles refer to STs that include two isolates; singleton STs consist of only one isolate. (C) Diversity of plasmids harboring bla_KPC. As above, the term doubles refers to plasmid clusters that include two plasmids. The small proportion of plasmids that did not share a secondary MOB-cluster designation with any other plasmid are denoted as nonclustering.