Protecting water sources from animal and fecal pollution for preventing ARGs contamination

The study aimed to explore the potential source of antibiotic resistance genes (ARGs) in environmental media, to better understand the sinks of ARGs among bacterial hosts in the environment, and to provide targeted recommendations for preventing contamination by ARGs. A clean ecosystem was selected, and the microbial communities and ARGs in water, soil, animals, and their parasitic vectors in this ecosystem were characterized using 16S rRNA gene sequencing and high-throughput quantitative PCR. Fast Expectation-maximization Microbial Source Tracking (FEAST) analysis was used for revealing the source of ARGs. Approximately 60 % of bacteria and ARGs were shared among different environmental media. The contribution of bacterial community structure to the formation of ARGs distribution was 47.1 %, which was 100 times that of mobile genetic elements (MGEs). Water contributed the most to the ARGs in soil and animals with 54.78 % and 19.40 %, respectively. However, 80 % of ARGs in water originated from the surface and intestinal microbiota of animals, while 17.81 % were derived from soil. Animals had little effect on ARGs in their surface-associated parasite vectors. While MGEs facilitate the horizontal transmission of ARGs, the distribution of ARGs is primarily shaped by bacterial community structure. In ecosystems, water bodies are the most critical medium for the dissemination of ARGs, yet they are vulnerable to contamination from animals. Compared to the ability of animal skin surface vectors to transmit pathogens, their ability to transmit ARGs is more limited. Preventing ARGs from polluting the environment hinges on protecting water sources from contamination by animals and feces.