Molecular epidemiology and genomic plasticity of ESBL-producing and carbapenem-non-susceptible Klebsiella pneumoniae in a tertiary care hospital in northern Thailand

in KP02 and KP05, the latter located on IncX3 plasmids co-harboring qnrS1 within an IS26-mediated composite transposon) and two isolates lacking carbapenemase genes. Virulence profiling identified limited hypervirulence determinants; one ST25/K2 isolate (KP06) carried a KpVP-1-like virulence plasmid, suggesting potential convergence of antimicrobial resistance and virulence. Overall, our findings indicate extensive ESBL dissemination across diverse lineages and show that carbapenem non-susceptibility can arise via both carbapenemase and non-carbapenemase mechanisms, highlighting the importance of ongoing genomic surveillance.