Canine saliva is a source of interspecies antimicrobial resistance gene transfer

Abstract

While the One Health issues of intensive animal farming are commonly discussed, keeping companion animals is less associated with the interspecies headway of antimicrobial resistance. With the constant advance of veterinary standards, antibiotics are regularly applied in companion animal medicine. Due to the close coexistence of dogs and humans, dog bites and other casual encounters with dog saliva (e.g. licking the owner) are common. According to our metagenome studies based on 47 new generation sequencing canine saliva datasets from 2020 and 2021 reposited in NCBI SRA by The 10,000 Dog Genome Consortium and the Broad Institute, canine saliva is rich in bacteria with predictably transferable antimicrobial resistance genes (ARGs). In the genome of potentially pathogenic Bacteroides, Capnocytophaga, Corynebacterium, Fusobacterium, Pasteurella, Porphyromonas, Staphylococcus and Streptococcus species, that are some of the most relevant bacteria in dog bite infections, ARGs against aminoglycosides, carbapenems, cephalosporins, elfamycin, glycylcyclines, lincosamides, macrolides, oxazolidinone, penams, phenicols, pleuromutilins, streptogramins, sulfonamides and tetracyclines could be identified. Several ARGs, including ones against amoxicillin clavulanate, the most commonly applied antibiotic by dog bites, was predicted to be potentially transferable based on their association with mobile genetic elements (e.g. plasmids, phages, integrated mobile genetic elements). According to our findings, canine saliva may be a source of transfer of ARG-rich bacteria, that can either colonize the human body or transport ARGs to the host bacteriota and thus can be considered as a risk in the spread of antimicrobial resistance.

Antimicrobial resistance among canine enterococci in the northeastern United States, 2007–2020

“…Household pets live in close contact with humans and pose a substantial risk for transmission of illnesses and drug-resistant pathogens to susceptible owners, pet shop employees, veterinarians, as well as other animals ( Rees et al, 2021 ). Novel resistance determinants continue to emerge in zoonotic pathogens and commensal bacteria isolated from household pets, mostly dogs and cats ( Jackson et al, 2009 ; Leonard et al, 2011 ; Cummings et al, 2015 ; KuKanich and Lubbers, 2015 ; Zhang et al, 2016 ; Bourély et al, 2019 ; Li et al, 2021 ; Hata et al, 2022 ; Tóth et al, 2022 ). Dogs are increasingly recognized as a potential reservoir and a relevant transmission pathway of commensal and pathogenic bacteria or their resistance genes ( Harada et al, 2012 ; Damborg et al, 2016 ; Francois Watkins et al, 2021 ).…”