Advancing antimicrobial resistance monitoring in surface waters with metagenomic and quasimetagenomic methods

Abstract

The National Antimicrobial Resistance Monitoring System (NARMS) has monitored antimicrobial resistance (AMR) associated with pathogens of humans and animals since 1996. In alignment with One Health strategic planning, NARMS is currently exploring the inclusion of surface waters as an environmental modality for monitoring AMR. From a One Health perspective, surface waters function as key environmental integrators between humans, animals, agriculture, and the environment. Surface waters however, due to their dilute nature present a unique challenge for monitoring critically important antimicrobial resistance. Selective enrichments from water paired with genomic sequencing effectively describe AMR for single genomes but do not provide data to describe a broader environmental resistome. Metagenomic data effectively describe a broad range of AMR from certain matrices however, depth of coverage is usually insufficient to describe clinically significant AMR from aquatic matrices. Thus, the coupling of biological enrichments of surface water with shotgun NGS sequencing has been shown to greatly enhance the capacity to report an expansive profile of clinically significant antimicrobial resistance genes. Here we demonstrate, using water samples from distinct sites (a creek in close proximity to a hospital and a reservoir used for recreation and municipal water), that the AMR portfolio provided by enriched (quasimetagenomic) data is capable of describing almost 30% of NARMS surveillance targets contrasted to only 1% by metagenomic data. Additionally, the quasimetagenomic data supported reporting of statistically significant (P< 0.05) differential abundance of specific AMR genes between sites. A single time-point for two sites is a small pilot, but the robust results describing critically important AMR determinants from each water source, provide proof of concept that quasimetagenomics can be applied to aquatic AMR surveillance efforts for local, national, and global monitoring.