Metagenomic Analysis Reveals Resistome Characteristics of Acidic, Multimetal(Loid) Enriched Coal Source Mine Drainage Environment Under Heavy Metal(Loid)S-Induced Co-Selection

Abstract

Heavy metal(loid) contaminations caused by mine activities have been treated as potential hotspots of antibiotic resistance genes (ARGs) because of heavy metal(loid)s-induced co-selection of ARGs and heavy metal(loid) resistance genes (MRGs), but the opinion has not been fully tested for lacking of relative researches. In this study, a metagenomic sequencing technique was used to analyze the resistome characteristics of a coal source acid mine drainage (AMD). We found multidrug efflux dominated antibiotic resistome, and highly diverse heavy metal(loid) resistome occupied by Hg-, Fe-, and As-resistance. Correlation analysis found that mobile gene elements (MGEs) exerted more influence on the dynamics of MRGs rather than ARGs. Most heavy metal(loid)s were significantly positively related with the multifunctional genes mdtB, acrB, and arnA rather than the corresponding MRGs. Among the metagenome-assembled genomes (MAGs), six potential pathogens carrying multi-RGs resistant to several antibiotics and heavy metal(loid)s were recovered, in which Pseudomonas spp. was found to contain the most numbers of RGs resistant to 2 kinds of antibiotic types, and 12 kinds of heavy metal(loid)s. The results demonstrated that high contents of heavy metal(loid)s drove the co-selection of ARGs, and MRGs. The occurrence of potential pathogens containing multi-RGs might cause ARG dissemination risks in the environment.

Keywords: Metagenomic, Resistome, Co-selection, Acid mine drainage, Multimetal(loid) contamination.