Capture of mobile genetic elements following intercellular conjugation promotes the production of ST11-KL64 CR-hvKP

The emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) heralded the onset of a new and rapidly worsening public health disaster on a global scale. More attention has been paid to its evolutionary history and mechanism, which currently remains unclear. In this study, a conjugation experiment was performed between a hvKP strain AP8555 and a ST11 CRKP strain, resulting in two ST11 CR-hvKP strains. We had confirmed that the virulence plasmid pAP855 was horizontally transferred to the CRKP strain to form the conjugant S270-Tc, which was recombined by mobile genetic elements to evolve into the conjugant S270-Tc-R. The S270-Tc-R had high virulence, high plasmid stability, and greater adaptability. Interestingly, it had high homology to clinically prevalent ST11 CR-hvKP strains using pulsed-field gel electrophoresis and whole-genome sequencing.