Extended-Spectrum Beta-Lactamase-ProducingIsolated from Healthy and Sick Dogs in Portugal.

Abstract

Extended-spectrum beta-lactamase (ESBL)- and carbapenemase (CP)-producingisolates are a public health concern at clinical level, mainly in Southern European countries. However, there are scarce data on the role of companion animals in the emergence of resistance to clinically relevant antibiotics. Therefore, our study aimed to determine the presence ofwith relevant beta-lactamases in fecal samples from healthy dogs (kennel and house dogs) and sick dogs in seven different hospitals in Portugal. Fecal samples from 125 healthy dogs and 231 sick dogs (one per animal) were collected during April-August 2017. Samples were screened on MacConkey agar supplemented with meropenem, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) was used foridentification. Genotypic detection of ESBLs or CPs was carried out by PCR/sequencing. Moreover, the presence of other antimicrobial resistance genes and multilocus sequence typing was tested by PCR/sequencing.isolates were obtained from 16 tested samples (4.4%), and 3 of them were ertapenem and/or meropenem intermediate/resistant (all of them imipenem susceptible and negative for CP genes). Fifteenisolates were ESBL producers, and they carried the following beta-lactamase genes:+(four isolates, in three cases associated with),+(five isolates, associated with TEM-1 in three cases), and+(six isolates). Three ESBL-producingisolates of different origins and beta-lactamase genotypes (CTX-M-15+SHV-28, CTX-M-15+SHV-28+TEM-1, or SHV-28+TEM-1) belonged to the lineage ST307, and one isolate was identified as ST15 (CTX-M-15+SHV-1). These findings highlight that dogs are frequent carriers of ESBL-producingisolates, harboring mostly genes encoding CTX-M-15 or SHV-28, associated in some cases with the high-risk clones ST307 and ST15.