Emergence of a Multidrug-Resistant Hypervirulent Klebsiella pneumoniae Sequence Type 23 Strain with a Rare bla CTX-M-24 -Harboring Virulence Plasmid.

Here, we report a multidrug-resistant hypervirulent Klebsiella pneumoniae (MDR-HvKP) strain of sequence type 23 (ST23) with a rare hybrid plasmid harboring virulence genes and bla(CTX-M-24), and we analyze the genetic basis for relationship between genotypes and MDR-hypervirulence phenotypes. Further analysis indicates that the hybrid plasmid is formed by IS903D-mediated intermolecular transposition of the bla(CTX-M-24) gene into the virulence plasmid. The emergence of MDR-HvKP strains, especially those carrying drug-resistant virulent plasmids, poses unprecedented threats/challenges to public health. This is a dangerous trend and should be closely monitored.