Insights into the Diversity of Gut Microbiota and Associated Antibiotic Resistance Genes in Healthy Dogs
Author(s): Pillai DK, Peterson G, and Zurek L
Aims: The study was conducted to analyze the gut microbial community and antimicrobial resistance genes in healthy dogs.
Methods and Results: Fecal samples from household dogs (n=10) were subjected to bacterial tag-encoded FLX amplicon pyrosequencing
(bTEFAP) and a spotted DNA microarray to identify antimicrobial resistance genes. Twelve distinct phyla were identified and Firmicutes
represented the most dominant phylum, followed by Fusobacterium. Two phyla, Lentisphaerae (<1%) and Fibrobacteres (<1%) are reported
for the first time from healthy dogs. A total of twelve different genera were identified across all the fecal samples tested. Notable genera
detected in all the fecal samples were Lactobacillus, Ruminococcus, Turicibacter, Clostridium, and Fusobacterium (each represented >2% of
the sequences). We observed dog to dog variation in the microbial community composition with respect to relative abundance and diversity
in bacterial taxa. The microarray data showed that overall prevalence of antibiotic and metal resistance in the fecal microbiota of healthy
dogs was low. Several antibiotic (tetracycline, erythromycin and aminoglycoside) and metal resistance genes (four copper resistance genes)
were detected. However, one dog with a history of antibiotic treatment for chronic skin disease had multiple AMR genes.
Conclusions: Our findings indicate that dog to dog variation occurs in the microbial community composition with respect to relative
abundance, diversity in bacterial taxa and antibiotic and metal resistance genes harbored by these microbes. There is low prevalence of
resistance genes in the healthy dogs. Significance and Impact of study: This is the first study to perform a microarray-based analysis of
antibiotic and metal resistance genes in the feces of healthy dogs with insights into the diversity of resistance genes in the gut microbiota of
healthy household dogs.