The host-specific resistome in environmental feces of Eurasian otters (Lutra lutra) and leopard cats (Prionailurus bengalensis) revealed by metagenomic sequencing

Investigation of feces of wildlife, which is considered as reservoirs, melting pots, vectors and secondary sources of antimicrobial resistance genes (ARGs), provides insights into the risks and ecology of ARGs in the environment. Here, we investigated microbiomes, virulence factor genes (VFGs) of bacterial pathogens, and resistomes in environmental feces of Eurasian otters (Lutra lutra) and leopard cats (Prionailurus bengalensis) using shotgun metagenome sequencing. As expected, the taxonomic compositions of bacteria were significantly different between the animals. Importantly, we found that the compositions of ARGs were also significantly different between the animals. We detected ARGs including iri, tetA(P), tetB(P), floR, sulII, strA, strB, tetW and tetY. Some of them were significantly more abundant in either of the host animals, such as strA, strB and tetY in Eurasian otters, and tetA(P), tetW and iri in leopard cats. We also found that some ARGs were selectively correlated to particular VFGs-related bacteria, such as tetA(P) and tetB(P) to Clostridium, and iri to Mycobacterium. We also found that there were positive correlations between Acinetobacter and ARGs of multiple antimicrobial classes. The host-specific resistomes and VFGs-related bacteria may be due to differences in the host's gut microbiome, diet and/or habitat, but further investigation is needed. Overall, this study provided important baseline information about the resistomes of the wildlife in Korea, which may help the conservation of these endangered species and assessment of human health risks posed by ARGs and bacterial pathogens from wildlife.