Mining-Related Multi-Resistance Genes in Typical Karst Nonferrous Metal(Loid) Tailing Impoundments Under Bio-Restoration

Abstract

Tailing impoundments as reservoirs of multi-resistance posed a threat to human health. Potential co-selection of antibiotic resistance genes (ARGs) with metal(loid) resistance genes (MRGs) during bio-restoration have been poorly investigated. Here we show that abundance of sulfonamide-related ARGs based on Metagenomic analysis decreased, whereas those related to bacitracin and chloramphenicol increased. Metal(loid)s contents (including As, Cd, Fe, Pb, Sb, and Zn) were the main drivers for microbial organization. Thiobacillus and Sphingomonas being the main genera carrying the bacA and mexef resistance operons, which were also found as main genera carrying MRGs together with Sulfuricella genus. The added SRB strains Desulfosporosinus and Desulfotomaculum, and acidophilic strain Acidiphilium significantly contributed to the distribution of sul genes, while Thiobacillus, Sphingomonas, Sulfuricella, and Meiothermus genera significantly contributed to the distribution of MRGs. Additionally, ARGs (mexNW, merD, sul and bla) and MRGs (czcABCR and copRS genes) were found on the same contig, revealing the co-selection of ARGs and MRGs. Co-selection of ARGs and MRGs should be considered for the implementation bio-restoration processes as they can impact human health. The study also shows the involvement of iron metabolism via Feo-like genes in bio-restoration process, providing new insights, useful for the management of tailings’ bio-restoration.

Keywords: Microorganism, Antimicrobial resistance, Metal resistance, Co-selection, Tailings impoundments