Objective To understand the resistance, virulence and other etiological characteristics of clinical hypervirulent and multidrug-resistant Klebsiella pneumoniae (MDR-hvKP) isolates in Yangzhou, Jiangsu province, from 2016 to 2024.

Methods The clinical isolates of K. pneumoniae were collected from six hospitals in Yangzhou during 2016-2024, and MDR-hvKP were identified based on the results of microbroth dilution method and whole-genome sequencing. The resistance phenotype, carriage of resistance genes and virulence factors, affinities of strains, as well as the carriage of bla_KPC-12 were analyzed.

Results A total of 358 K. pneumoniae strains were collected, in which 59 MDR-hvKP strains were isolated. The results of drug susceptibility test showed that the resistance rates to chloramphenicol, sulfonamides, cephalosporins, ampicillin-sulbactam, monocyclic lactams, tetracyclines, and quinolones all exceeded 55.00%, and the resistance rates to all three carbapenem antimicrobials exceeded 40.00%. Thirty-eight resistance phenotypes were detected, of which 18 strains were not sensitive to 16 antibiotics, and 36 resistance determinants in nine categories were identified. The detection rates of major virulence factors iucABCD, iroBCDN, rmpA, rmpA2 and peg-344 were more than 50.00%. ST11 was the predominant sequence type (ST), and ST700 was the predominant in some areas in the past two years, and there were significant clustering of the strains with same ST as well as strains in different years. Potential splice plasmids carrying the rare carbapenem resistance gene bla_KPC-12 were found.

Conclusion The drug resistance and virulence of MDR-hvKP was severe in Yangzhou during 2016−2024. ST11 was the predominant ST, which might result in the persistence and spread of MDR-hvKP in recent years through the mobile element.