Convergence of carbapenemase and hypervirulence-associated genes among Klebsiella pneumoniae high risk clones in Hungary

Introduction: Strains of Klebsiella pneumoniae that carrying hypervirulence with carbapenemase genes represent a rapidly emerging global public health threat. Our study aimed to comprehensively characterise the genomics of hypervirulent and carbapenemase-producing K. pneumoniae (hvCPKP) isolates in Hungary.Materials and methods: Between January 2023 and April 2024, 89 non-duplicate K. pneumoniae isolates from 15 Hungarian healthcare institutes underwent short-read (Illumina, MiSeq, NextSeq) whole-genome sequencing, followed by detailed plasmid analysis using long-read sequencing (Nanopore, MinION) in a representative subset of 32 strains.Results: Most isolates (79/89) belonged to the high-risk clone ST147. Hypervirulence-associated genes - including rmpA/rmpA2, peg344, shiF, iucA-D, and iutA - were universally present, and 59 isolates possessed chromosomally integrated yersiniabactin loci. Most isolates (87/89) carried the blaNDM-1 carbapenemase gene. Plasmid analysis identified 88 plasmids. Hypervirulence genes were most frequently (31/32) associated with IncHI1B/IncFIB(Mar) plasmids. Notably, we detected hybrid plasmids carrying both hypervirulence and carbapenemase genes in 13/32 strains. The blaNDM-1 region was linked to IS26 transposase and present in conserved cassettes on all plasmids.Discussion/Conclusion: Our study identified hvCPKP strains, particularly the ST147 clone, circulating in Hungary. Our findings highlight the need for routine virulence gene monitoring and continuous genomic and plasmid-based surveillance to mitigate the clinical and epidemiological impact of emerging hvCPKP lineages.