ABSTRACTDissemination of hypervirulent and carbapenem-resistantKlebsiella pneumoniae(CRKP) has been reported worldwide, posing a serious threat to antimicrobial therapy and public health. Outer membrane vesicles (OMVs) act as vectors for the horizontal transfer of virulence and resistance genes. However,K. pneumoniaeOMVs that transfer carbapenem resistance genes into hypervirulentK. pneumoniae(hvKP) have been insufficiently investigated. Therefore, this study investigates the transmission of theblaNDM-1gene encoding resistance via OMVs released from CRKP and the potential mechanism responsible for the carbapenem-resistant hypervirulentK. pneumoniae(CR-hvKP) emergence. OMVs were isolated via ultracentrifugation from CRKP with or without meropenem selective pressure. OMVs were then used to transform classicalK. pneumoniae(ckp) ATCC 10031, extended-spectrum β-lactamase (ESBL)-producingK. pneumoniaeATCC 700603, and hvKP NTUH-K2044. Our results showed that meropenem treatment resulted in changes in the number and diameter of OMVs secreted by CRKP. OMVs derived from CRKP mediated the transfer ofblaNDM-1to ckp and hvKP, thereby increasing the carbapenem MIC of transformants. Further experiments confirmed that NTUH-K2044 transformants exhibited hypervirulence. Our study demonstrates, for the first time, that OMVs derived from CRKP can carryblaNDM-1and deliver resistance genes to otherK. pneumoniaestrains, even hvKP. The transfer of carbapenem genes into hypervirulent strains may promote the emergence and dissemination of CR-hvKP. This study elucidates a new mechanism underlying the formation of CR-hvKP.