Background: The emergence of Klebsiella pneumoniae carrying carbapenemase-genes with associated hypervirulence, causing invasive infections, is a concern in human health; its impact in veterinary medicine however remains unknown.
Objective: To assess the presence of carbapenemase-producing K. pneumoniae causing invasive infections in companion animals (CA).Animals: The study was performed on a collection of 4293 Enterobacterales isolates obtained during 2020 to mid-2023 from samples submitted for microbiological analysis originating from CA with suspected infection.
Methods: Beta-lactam resistance was screened using CRE (Carbapenemase Resistant Enterobacterales) Agar selective media (CRS), and confirmation of species as K. pneumoniae was performed by PCR. Positive isolates were further evaluated by disc diffusion for resistance to other beta-lactams; a string test was performed to screen for hypervirulence. Carriage of carbapenemases was confirmed by PCR and sequencing.
Results: A total of 107 CRS positive isolates were PCR-confirmed as K. pneumoniae (2.5% of all isolates). CRS K. pneumoniae isolates originated from UTIs (52.3%; n=56/107), skin and soft tissue infections (39.3%; n=42/107), and respiratory infections (8.4%; n=9/107). Six isolates were carbapenemase gene carriers, identified as two carrying the blaKPC-3 gene, three blaOXA-181, and one blaOXA-48 which was previously undetected in CA in Portugal. Three CRS isolates were string test-positive but lacked detectable carbapenemase genes.
Conclusions: Low prevalence and absence of inclusion and/or harmonization of routine screening methods for carbapenem resistance in veterinary clinical microbiology laboratories may be hindering epidemiological surveillance of this relevant virulent and resistant phenotype of this pathogen with important animal and public health impact.
