摘要
      重金属污染和环境中抗生素耐药性的共同选择的可能性越来越令人担忧。然而，重金属与河流系统中抗生素耐药性之间的明确联系尚未形成。在这里，我们研究了总重金属浓度和生物可利用重金属浓度之间的关系；金属抗性基因（MRG）和抗生素抗性基因（ARG）的丰度；流动遗传元素；以及英国和印度低金属和高金属污染河流中当地细菌群落的组成。结果表明，对钴（Co）和镍（Ni）、钴、锌和镉（czcA）具有抗性的MRGs和对碳青霉烯和红霉素具有抗性的ARGs是整个样品的主要抗性基因。在高金属污染的环境中，相对MRGs、ARGs和整合子丰度往往会增加，这表明高金属浓度有很强的潜力通过水平基因传播促进金属和抗生素耐药性，并影响细菌群落，导致多金属和多抗生素耐药性的发展。网络分析表明，MRG和ARGs之间存在积极而显著的关系，整合子在MRG和ARGs的共同传播中发挥作用的潜力（r>0.80，p<0.05）。此外，通过网络分析还确定了各种MRG和ARGs的主要宿主细菌，这些细菌可能对高金属污染环境中更高的MRG和ARGs水平负责。Spearman的秩序相关性和RDA分析进一步证实了总重金属和生物可利用重金属浓度与相对MRG、ARG和整合素丰度以及相关细菌群落组成之间的关系（r>0.80（或<−0.80），p＜0.05）。这些发现对于评估与金属驱动的抗生素耐药性相关的可能的人类健康问题至关重要，并强调需要考虑金属污染，以制定适当的措施来控制ARG的传播。
Abstract
Heavy metal pollution and the potential for co-selection of resistance to antibiotics in the environment is growing concern. However, clear associations between heavy metals and antibiotic resistance in river systems have not been developed. Here we investigated relationships between total and bioavailable heavy metals concentrations; metal resistance gene (MRG) and antibiotic resistance gene (ARG) abundances; mobile genetic elements; and the composition of local bacterial communities in low and high metal polluted rivers in UK and India. The results indicated that MRGs conferring resistance to cobalt (Co) and nickel (Ni) (rcnA), and Co, zinc (Zn), and cadmium (Cd) (czcA), and ARGs conferring resistance to carbapenem and erythromycin were the dominating resistant genes across the samples. The relative MRGs, ARGs, and integrons abundances tended to increase at high metal polluted environments, suggesting high metals concentrations have a strong potential to promote metal and antibiotic resistance by horizontal gene transmission and affecting bacterial communities, leading to the development of multi-metal and multi-antibiotic resistance. Network analysis demonstrated the positive and significant relationships between MRGs and ARGs as well as the potential for integrons playing a role in the co-transmission of MRGs and ARGs (r > 0.80, p < 0.05). Additionally, the major host bacteria of various MRGs and ARGs that could be accountable for greater MRGs and ARGs levels at high metal polluted environments were also identified by network analysis. Spearman's rank-order correlations and RDA analysis further confirm relationships between total and bioavailable heavy metals concentrations and the relative MRG, ARG, and integron abundances, as well as the composition of related bacterial communities (r > 0.80 (or < −0.80), p < 0.05). These findings are critical for assessing the possible human health concerns associated with metal-driven antibiotic resistance and highlight the need of considering metal pollution for developing appropriate measures to control ARG transmission.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122005401