Fatal septicemia caused by human-associated NDM-5-producing Klebsiella pneumoniae ST323 clone in a dog.

Abstract

Carbapenemase-producing Enterobacterales (CPE), particularly those harboring New Delhi Metallo-β-lactamase (NDM), represent a growing global health threat due to their resistance to carbapenems and other β-lactam antimicrobials. While the presence of NDM-producing Klebsiella pneumoniae is well-documented in human healthcare settings, its emergence in companion animals remains a critical concern. This study reports the identification and genomic characterization of an NDM-5-producing K. pneumoniae strain (ICBKPJB) isolated from an infected dog in Brazil. Strain ICBKPJB exhibited a multidrug resistance profile, including to carbapenems, and carried multiple antimicrobial resistance genes, highlighting blaand bla. Whole-genome sequencing revealed that ICBKPJB belongs to the human healthcare-associated clone of the sequence type (ST) 323, whereas phylogenomic analysis grouped the ICBKPJB strain with human and environmental ST323 strains (SNP counts ranging from 95 to 147). The presence of an IncX3 plasmid harboring the blagene was confirmed, whereas in silico plasmid analysis demonstrated that it was closely related to plasmids found in K. pneumoniae strains from both humans and animals worldwide. These findings underscore the risk of interspecies transmission of CPE and emphasize the need to strengthen alliances between human and veterinary medicine to address the emergence, spread, and circulation of carbapenem resistance across both sectors.