Prevalence of hypervirulent and carbapenem-resistant <i>Klebsiella pneumoniae</i> under divergent evolutionary patterns

Abstract

K1/K2 hvKP strains acquire carbapenem-resistance plasmids, known as CR-hvKp, and carbapenem-resistant <i>Klebsiella pneumoniae</i> (CRKP) strains obtain virulence plasmids, recognized as hv-CRKP. The two different evolution patterns of hypervirulent combined carbapenem-resistant <i>Klebsiella pneumoniae</i> may lead to their different prevalence in hospitals. Our study aimed to investigate the prevalence of hv-CRKP and CR-hvKp strains and to analyze factors influencing their evolution and prevalence. We collected 890 <i>K. pneumoniae</i> genomes from GenBank and 530 clinical <i>K. pneumoniae</i> isolates from nine hospitals. Our study found that hv-CRKP strains were more prevalent than CR-hvKp strains and both were dominated by <i>bla</i>_KPC-2 gene. The <i>bla</i>_KPC-2-carrying plasmids could mobilize non-conjugative virulence plasmids from hvKp strains to CRKP strains. The conserved <i>oriT</i> of virulence plasmids and the widespread of conjugative helper plasmids were potential factors for the mobilization of non-conjugative virulence plasmids. HvKp strains with KPC plasmid could hardly simultaneously exhibit hypervirulence and carbapenem resistance as CRKP strains with virulence plasmid, and we found that <i>rfaH</i> mutation reduced capsular synthesis and increased carbapenem resistance of the CR-hvKp strain. In summary, this study revealed that hv-CRKP strains were more suitable for survival in hospital settings than CR-hvKp strains and the widespread conjugative KPC-producing plasmids contributed to the emergence and prevalence of hv-CRKP strains.