Genomic Analysis of Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae in a Chinese Tertiary Hospital.

BACKGROUND: Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) has become a clinical crisis and is associated with significant morbidity and mortality. The prevalence of CR-hvKP has trended upward since 2010. This study aims to describe the clinical and genomic characteristics of CR-hvKP collected from a tertiary hospital in eastern China, from August 2020 to October 2021.

METHODS: We tested the susceptibility to common antibiotics in these isolates to feature the antibiotic-resistant phenotypes. We also applied whole-genome sequencing and core-genome phylogenetic to analysis the genetic features of these isolates. Plasmid replicons were identified by using the PlasmidFinder database, and core-genome phylogenetic analysis by Parsnp database.

RESULTS: All these strains isolated from the patients with serious underlying diseases and poor prognosis. We found all CR-hvKp isolates exhibited a multidrug-resistant (MDR) phenotype. These results revealed that bla KPC-2 was the predominant carbapenemases gene (n = 53, 84.1%), and ST11-KL64 CR-hvKP strains dominated, forming a single cluster, and differed by an average of 26 core SNPs. We only found eight ST15 isolates containing KL24 and KL112 type capsules, with the main carbapenem resistance genes being bla OXA-232 and bla KPC-2 . All ST11-KL64 strains had a series of resistance and virulence genes, along with IncHIB-FIB virulence plasmids and IncFII resistance plasmids, while the prevalence of resistance plasmids like the IncFII plasmid was absence in ST15 isolates.

CONCLUSION: This suggests that ST11-KL64 CR-hvKP has emerged as the most prevalent hypervirulence and carbapenem-resistant K. pneumoniae and may contribute to hospital outbreaks of infection, which required most clinical attention.