Abstract: Antimicrobial resistance (AMR), caused by antibiotic resistance genes (ARGs), is a growing threat to human health. Deciphering of ARG hosts is crucial for assessing the risk of AMR transmission from environment to human pathogens. Currently, ARG hosts in remote and pristine areas are poorly understood. Here, based on metagenomic data from Antarctic Union Glacier areas, the distribution pattern, resistance mechanism, and migration potential of ARG hosts were investigated by using metagenomic assembly and binning methods. A total of 80 MAGs (metagenomeassembled genomes) were constructed in the Antarctic Union Glacial soils, of which 18 MAGs could carry 86 ARGs (13 ARG types). The most commonly detected ARG types were related to multidrug, aminocoumarin, rifampicin, glycopeptide, and bata-lactams. Different ARGs present different host association resistance patterns. In the ARG hosts, 21 ACCs (ARG-carrying contigs) were found to carry MGEs (mobile genetic elements). Among those MDEs, translocase is the most common one, followed by transposase, integrase, conjugated transfer protein and recombinase. The MGEs and ARGs formed certain ARG-MGE co-existence patterns to promote the spread of AMR. In addition, due to carrying multiple ARGs, Escherichia, Burkholderiaceae, and Nocardioides members were important ARG repositories in Union Glacier soils. Together, these results provided basis for the risk assessment and control of environmental antibiotic resistance.

Key words: antibiotic resistance gene, metagenomic binning, ARG host, mobile genetic element, Antarctic Union Glacier.