Abstract

The constant isolation of antimicrobial-resistant bacteria from animals poses a serious risk to public health, due to the close relationship between humans and domestic animals such as dogs, cats, and horses, mainly. Antimicrobial resistance determinants can be spread among bacterial populations from the community or hospital and transmitted to people in close contact with animals, such as their owners and veterinary staff. We characterize the antimicrobial resistance and the genetic relationship among five Klebsiella pneumoniae multidrug-resistant isolated from canine and one isolated from a horse in a Veterinary Teaching Hospital in Brazil. Antimicrobial resistance was investigated using disk diffusion assay and ESBL genes by PCR. Identification of the Klebsiella species and phylogroups was performed by combining the PCR and RFLP techniques. Inc/replicons groups were detected by PCR-based replicon typing and clonal relatedness was assessed by pulsed-field gel electrophoresis. The six isolates were identified as multidrug-resistant (MDR) K. pneumoniae belonging to phylogenetic group KpI. blaCTX-M, blaSHV, and blaTEM genes were found, and blaTEM was present in all ESBL-positive strains (5/6=83.3 %), and Inc/replicons groups harbored (HI2, X, L/M, FIC, and K), associate with ESBL genes dissemination. PFGE showed genetic similarity (> 95 %) between one strain from a dog and another from the horse. This study revealed that different animal species carry multidrug-resistant bacterial clones that can be disseminated in the environment, to other animal species and humans. In this way, the widespread use or the misuse of antimicrobials may contribute to generating a population of resistant bacteria, including K. pneumoniae.