Proof-of-concept of host attribution of antimicrobial resistance genes using wastewater Hi-C metagenome sequencing

The proliferation of antimicrobial resistance genes (ARGs) poses public health risks globally, with wastewater treatment plants (WWTPs) serving as dissemination hubs for horizontal gene transfer. In this study, we evaluated the potential of applying Hi-C sequencing coupled with metagenomic bioinformatics for surveillance of ARGs and other microbial fitness traits using samples from WWTPs. Hi-C sequencing has the advantage over other molecular approaches by directly associating genes conveying fitness to their host microbe, plus to their element type (in plasmids, phages, or within the core genome of its host microbe). Results from Hi-C analyses confirm results from more laborious approaches by showing that aminoglycoside resistance is disseminated by plasmids. Mercury resistance was found in Zoogloea bacteria. Resistance genes to quaternary ammonium compounds were found within bacteriophages. Results from this study provide proof-of-concept for the potential value of Hi-C metagenome sequencing in wastewater attribution studies by illustrating the breadth of information that can be obtained about the microbial community, the exchange of genes, and their interconnections. We believe that with further development, Hi-C sequencing can be integrated into routine monitoring of wastewater for the purpose of providing near-real-time information about the dissemination of fitness traits, including ARGs.