Clonal overlap and resistance profiles of multidrug-resistant Klebsiella pneumoniae in humans and domestic animals in Brazil: A One Health molecular epidemiology study

Background and Aim: The global rise of multidrug-resistant (MDR) Klebsiella pneumoniae poses a serious threat to human and animal health. Close proximity between humans and domestic animals may facilitate zoonotic transmission of MDR strains, underscoring the need for integrated surveillance strategies. This study aimed to investigate the genetic diversity, resistance mechanisms, and virulence gene profiles of K. pneumoniae isolates from domestic animals and humans in Mato Grosso, Brazil, within the One Health framework. Materials and Methods: A total of 48 clinical isolates (33 from animals and 15 from humans) were analyzed. Identification was confirmed through 16S ribosomal RNA sequencing. Antimicrobial susceptibility was tested using disk diffusion (animal isolates) and minimum inhibitory concentration (human isolates). Resistance (blakpc-2 and blaNDM) and virulence genes (entB, fimH, wabG, ugE, etc.) were detected through polymerase chain reaction. Multilocus sequence typing (MLST) was performed on seven housekeeping genes, and sequence types (STs) were assigned using the Pasteur Institute database (Paris, France). Results: MDR phenotypes were found in 70.83% (34/48) of isolates – 78.78% of animal and 53% of human samples. Virulence genes were present in 77.08% of isolates; entB was the most prevalent (60.61%). The blakpc-2 gene was found in three human isolates, and blaNDM was found in one human and one bovine isolate. MLST revealed 39 STs, including 9 novel ones. Clonal complexes (CC)258 (human), CC15 (animal), and CC147 (both species) indicated potential interspecies transmission. Conclusion: This study provides the first comprehensive molecular epidemiological snapshot of K. pneumoniae in domestic animals and humans in Mato Grosso. The discovery of shared clonal complexes and high MDR rates demands urgent cross-sectoral surveillance and control strategies under the One Health approach. Keywords: blaKPC-2, blaNDM, Brazil, multidrug-resistant Klebsiella pneumonia, multilocus sequence typing, one health, virulence genes, zoonotic transmission.