Epidemiological, phenotypic and genotypic characteristics difference of hypervirulent and carbapenem-resistant Klebsiella pneumoniae with different capsular serotypes.

BACKGROUND

KL1, KL2 CR-hvKP and KL64, KL47 hv-CRKP all exhibit overlapping multidrug resistance and hypervirulence phenotypes, but the differences in epidemiological, phenotypic and genotypic characteristics between them remains unclear.

METHODS

In this study, we collected non-repeated hv-CRKP/CR-hvKP isolates in a tertiary hospital in Shanghai, China from January 2019 to December 2022. Furthermore, we selected four typical hypervirulent and carbapenem-resistant Klebsiella pneumoniae, including ST23-KL1/ST86-KL2 CR-hvKP (WYKP3 and WYKP194) and ST11-KL64/ST11-KL47 hv-CRKP (WYKP589 and WYKP188), and tried to clarify and compare their differences in virulence and drug resistance characteristics and plasmid distribution.

RESULTS

Our study found that ST23-KL1 and ST86-KL2 CR-hvKP exhibited less plasmid diversity than that of ST11-KL64 and ST11-KL47 hv-CRKP. Compared with ST11-KL64 and ST11-KL47 hv-CRKP, ST23-KL1/ST86-KL2 CR-hvKP harbored significantly fewer antimicrobial resistance genes but more virulence genes, which contributed to the higher virulence of these strains and exhibited resistance to fewer antibiotics. ST11-KL64 hv-CRKP has emerged as the most prevalent hypervirulent and carbapenem-resistant Klebsiella pneumoniae probably due to its clonal transmission within hospitals as well as the transmission of virulence plasmids with the help of conjugative resistance plasmids.

CONCLUSIONS

Due to the different evolutionary mechanisms of hypervirulent and carbapenem-resistant Klebsiella pneumoniae with different capsular serotypes, the epidemiological, phenotypic and genotypic characteristics of KL1, KL2 CR-hvKP and KL64, KL47 hv-CRKP are different.