Genomic Characterization of Carbapenemase-Producing Klebsiella pneumoniae ST895 Isolates from Canine Origins Through Whole-Genome Sequencing Analysis

The widespread application of carbapenems and other broad-spectrum antibiotics has significantly escalated the threat posed by highly drug-resistant <i>Klebsiella pneumoniae</i> to human public health. In this research, we isolated a carbapenem-resistant <i>K. pneumoniae</i> strain from the feces of pet dogs at a veterinary hospital in Changchun, Jilin Province, China. To gain insights into its genetic makeup and resistance mechanisms, we conducted comprehensive whole-genome sequencing and antimicrobial susceptibility testing on the isolated strain. Our findings revealed the presence of three distinct plasmids within the strain, classified as IncFIB&IncFII, IncR, and IncX3. Notably, the bla<i>_NDM-5</i> gene, conferring resistance to carbapenems, was uniquely harbored on the IncX3 plasmid, which was devoid of any other resistance genes beyond bla<i>_NDM-5</i>. In contrast, the remaining two plasmids, IncFIB&IncFII and IncR, were found to encode an array of additional drug resistance genes, contributing to the strain's broad-spectrum resistance phenotype. The IncX3 plasmid, specifically, measures 45,829 bp in length and harbors the IS<i>5D</i>-bla<i>_NDM-5</i>-Ble-MBL-PRAI cassette, which has been closely linked to the dissemination of bla<i>_NDM-5</i> genes in <i>K. pneumoniae</i> strains. We reported the bla<i>_NDM-5</i>-carrying IncX3 in <i>K. pneumoniae</i> isolates recovered from the pet dog and revealed the molecular characterization. Emphasis should be placed on, and continuous monitoring carried out for, the dissemination of <i>K. pneumoniae</i> harboring the bla<i>_NDM-5</i> gene among humans, companion animals, and their related environments.