The effect of pet dog exposure on gut antibiotic resistome and microbiome of their owners.

Pet dogs exhibited significantly higher gut abundance of antibiotic resistance genes compared to their human owners and non-dog owners.

• Metagenomic analysis was used to compare ARG profiles across pet dogs, dog owners, and non-dog owners.
• Pet dogs served as reservoirs of ARGs with notably elevated overall ARG abundance relative to humans.
• The study design allowed direct comparison of resistome profiles between cohabitating humans and their pets.

Pet dogs harbored significantly higher gut abundance of ESKAPE pathogens, specifically Enterococcus faecium and Acinetobacter baumannii, compared to humans.

• ESKAPE pathogens are a group of clinically significant antibiotic-resistant bacteria.
• Both Enterococcus faecium and Acinetobacter baumannii were detected at higher levels in dog guts than in human guts.
• This finding was identified through metagenomic analysis of fecal samples from dogs and their owners.

Dog owners had significantly higher abundance of specific aminoglycoside resistance genes compared to non-dog owners.

• The aminoglycoside resistance genes aac(6')-Im and aac(6')-Ie-aph(2'')-Ia were significantly more abundant in dog owners than in non-dog owners.
• These genes were identified through shotgun metagenomic sequencing of gut microbiome samples.
• The difference in aminoglycoside resistance gene abundance suggests a transfer or sharing effect associated with pet dog cohabitation.

Dog owners had significantly higher abundance of specific tetracycline resistance genes compared to non-dog owners.

• The tetracycline resistance genes tetO and tet40 were significantly more abundant in dog owners than in non-dog owners.
• These resistance genes were detected via metagenomic analysis of human gut samples.
• The elevated tetracycline resistance gene abundance in dog owners mirrors patterns seen in their pet dogs.

Enterobacteriaceae were identified as shared core ARG hosts in both dog and human guts.

• Analysis of ARG-carrying bacterial taxa revealed Enterobacteriaceae as a common host family across both dogs and their owners.
• This shared bacterial family may serve as a vehicle for ARG transmission between dogs and humans.
• The finding was derived from metagenomic co-occurrence and host-tracking analyses within the study dataset.

The study used metagenomic analysis to characterize gut microbiome composition, ARG profiles, and mobile genetic elements across three groups.

• Three comparison groups were included: pet dogs, dog owners, and non-dog owners.
• Both ARG profiles and mobile genetic elements (MGEs) were characterized in addition to microbiota composition.
• MGEs are relevant because they can facilitate horizontal gene transfer of resistance genes between bacteria and across hosts.

Cohabitation with pet dogs is associated with correlated patterns of ARGs and resistant microbes between dogs and their owners.

• The overall resistome profiles of dog owners showed similarities to those of their pet dogs compared to non-dog owners.
• The shared resistome reflects both shared ARG types and shared ARG-hosting bacterial taxa.
• These results were interpreted as evidence of bidirectional or dog-to-human transmission of resistance determinants through close contact.