Work

Hybrid plasmids: genetic diversity and hypervirulent phenotype of Klebsiella pneumoniae

Year: 2026

Type: article

Abstract: Background The emergence of hybrid plasmids carrying virulence and multidrug resistance genes in Klebsiella pneumoniae can pose a serious public health challenge. However, data on their association with the hypervirulent phenotype of Klebsiella pneumoniae are contradictory. Methods We performed whole-genome sequencing of 32 K. pneumoniae isolates recovered from patients and environmental surfaces in eight Russian hospitals. The virulence of 7 isolates was assessed using a mouse lethality assay. We conducted cluster analysis of the global population of hybrid plasmids from K. pneumoniae ( n = 295) based on their nucleotide sequences. Results Whole-genome sequencing showed that the majority of isolates (27/32) carried hybrid plasmids (~272–476 kb), which simultaneously harboring virulence genes ( iucABCD , iutA , and rmpA2 ), and antibiotic resistance genes (ARGs), including bla OXA-48 . The LD 50 values for the tested isolates were > 10 6 CFU, a dosage comparable to classical K. pneumoniae . Analysis of the global population of hybrid plasmids identified 8 clusters, that showed concordance with replicon type, ARGs, and virulence genes. The majority of the K. pneumoniae isolates carrying hybrid plasmids belonged to ST147, ST395, and ST11. Conclusion Data regarding the hypervirulence of convergent of K. pneumoniae isolates are contradictory. Further studies are needed to understand the genetic basis of the differences in virulence among convergent K. pneumoniae isolates, carrying hybrid plasmids.

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1768089