Abstract
The global dissemination of multidrug-resistant Klebsiella pneumoniae (MDR-KP) poses a critical One Health challenge. This study investigated the antimicrobial resistance (AMR) profiles, virulence determinants, and zoonotic transmission risks of K. pneumoniae isolates from humans (n = 10) and animals (n = 42), including bovine, porcine, and avian sources (ducks), in Central China. Whole-genome sequencing and phenotypic assays revealed a high prevalence of multidrug resistance (MDR) (92.3%, 48/52) among K. pneumoniae isolates, with host-specific resistance rates: 100% in isolates from bovine and ducks, 90.9% in porcine isolates, and 70% in human isolates. Phylogenetic analysis revealed clustering of animal-derived sequence types (ST35, ST101, and ST592) with human clinical isolates, indicating potential cross-species transmission. No convergence of high virulence and MDR was observed. A representative ST11-KL64 strain (KP-HB21H30845) exhibited low virulence despite harboring canonical virulence gene clusters (iuc, rmpA, and iroN). Genetic characterization identified a 45-bp deletion within the rmpA promoter region, located within an ISKpn26-formed composite transposon on plasmid pKP845_1, which likely disrupts gene expression. Adjacent to iroN genes positioned near ISKpn26 insertion sites may face transcriptional interference, contributing to attenuated virulence phenotypes. The plasmid-borne existence of AMR determinants (bla(KPC-2) and bla(CTX-M-65)) and virulence loci (iuc and ybt on ICEKp) highlights the emerging risk of MDR hypervirulent K. pneumoniae (MDR-hvKP). These findings underscore the urgent need for integrated surveillance and antimicrobial stewardship across human-animal interfaces to mitigate MDR-KP dissemination in both veterinary and clinical environments. IMPORTANCE: MDR K. pneumoniae strains (ST35, ST101, and ST592) from animal hosts show genomic linkage to clinical human isolates, signaling interspecies transmission risks. The attenuated virulence of the ST11-KL64 is attributed to ISKpn26-mediated suppression of rmpA expression, a key regulator of hypervirulence in K. pneumoniae.