摘要

      细菌中的重金属抗性基因（MRGs）和抗生素抗性基因（ARGs）对重金属的诱导有反应。然而，MRGs和ARGs在长期重金属污染区的共存情况仍不清楚。本文研究了中国北方某铜尾矿坝区土壤细菌MRGs、ARGs含量与重金属污染的关系。我们发现，arsC和ereA基因分别编码对砷和大环内酯类药物的抗性机制，是研究区内最丰富的MRG和ARG基因。磁共振波谱的丰度与镉浓度呈正相关，说明镉在磁共振波谱选择中的重要性。网络分析结果表明，在重金属污染土壤中，sulII和MRGs与ARGs共存，copB与ARGs共存，表明MRGs和ARGs可以在重金属污染土壤中共存。网络分析也揭示了Cd与MRGs的共存，因此具有高毒性反应因子的重金属可以作为MRGs的指标。本研究进一步加深了对细菌耐药性与多金属污染关系的认识，为探索微生物在多金属污染环境中的适应机制奠定了基础。

       Heavy metal resistance genes (MRGs) and antibiotic resistance genes (ARGs) in bacteria can respond to the inducement of heavy metals. However, the co-occurrence of MRGs and ARGs in the long-term heavy metal contaminated area is still poorly understood. Here, we investigated the relationship between the abundance of soil bacteria MRGs, ARGs and heavy metal pollution in a copper tailing dam area of northern China. We found that arsC and ereA genes coding for resistance mechanisms to arsenic and to macrolides, respectively, are the most abundant MRG and ARG in the study area. The abundance of MRGs is positively correlated with cadmium (Cd) concentration, and this indicates the importance of Cd in the selection of MRGs. The network analysis results show that sulII and MRGs co-occur and copB occur with ARGs, which suggests that MRGs and ARGs can be co-selected in the soil contaminated by heavy metal. The network analysis also reveals the co-occurrence of Cd and MRGs, and thus heavy metal with a high 'toxic-response' factor can be used as the indicator of MRGs. This study improves the understanding of the relationship between bacterial resistance and multi-metal contamination, and underlies the exploration of the adaptive mechanism of microbes in the multi-metal contaminated environment.

       https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6710345/