Recent Advances in Heavy Metals-mediated Conjugation of Antibiotic Resistance Genes.

Cross-interface spread and aggregation of antibiotic resistance genes (ARGs) at human-animal-environment has become a major problem in public health and environmental ecosystems, ARGs and mobile genetic elements (MGEs) carrying ARGs have been recognized as emerging environmental contaminants. Heavy metal-mediated horizontal transfer of ARGs increases the potential risk of ARG enrichment in indigenous microorganisms. Currently, the study of horizontal transfer of ARGs mediated by heavy metals and other emerging contaminants has become a hot research topic in the field of environment and its related disciplines. The review outlines the effects of heavy metals as co-selectants on the conjugation of ARGs in the environment, focusing on the mechanisms associated with the increased conjugation of ARGs induced by heavy metals from a molecular biological perspective. The heavy metal-mediated conjugation of ARGs was the main reason for the increased abundance of ARGs, and the heavy metal-induced changes in conjugation frequency were mainly related to their concentrations, which is consistent with the hormesis. Related regulatory mechanisms include regulation of reactive oxygen species (ROS) production and initiation of SOS responses, enhancement of cell membrane permeability, and effects on conjugation transfer-related gene expression and ATP synthesis. Elucidation of the mechanisms that enhance the horizontal transfer of ARGs in contaminated environments with heavy metals (or compound heavy metals) and antibiotics under different environmental conditions is a key direction for future research. It can provide some reference for the study of heavy metal-mediated environmental behavior of ARGs. [ABSTRACT FROM AUTHOR]