Removing antibiotic resistance genes under heavy metal stress with carbon-based materials and clay minerals: By sorption alone?

Abstract

Antimicrobial resistance (AMR), especially antibiotic resistance, has posed a huge threat to public health. Moreover, heavy metal, another significant contaminant, can accelerate the generation and dissemination of AMR. Thus, the method and mechanism of AMR removal under heavy metal stress need to be elucidated urgently. Adsorption has been proved to be an important means to deal with AMR pollution. However, there is still a lack of systematic reviews on decontaminating the combined pollution of AMR and heavy metal by adsorption. With this in mind, this review introduces two types of adsorbents, carbon-based materials (biochar and graphene oxide) and clay minerals, which can remove antibiotic resistance genes (ARGs) efficiently even under heavy metal stress. Besides, we summarize the crucial factors affecting the variations of ARGs, and the mechanisms of ARGs removal by two materials under the influences of these factors are proposed. Then, the pathways of two materials to decrease ARGs by reducing heavy metal co-selection and altering microbial communities under heavy metal stress are emphasized. Finally, the bottlenecks of the research on reducing ARGs by these adsorbents and the prior study directions in the future are described in detail. To sum up, the review offers new insight into the mitigation of AMR and heavy metal pollution and facilitates the progress of feasible methods for the removal of ARGs and heavy metal.