There is an emerging field to put into practice new strategies for developing molecules with antimicrobial properties. In this line, several metals and metalloids are currently being used for these purposes, although their cellular effect(s) or target(s) in a particular organism are still unknown. Here we aimed to investigate and analyze Au3+ toxicity through a combination of biochemical and molecular approaches. We found that Au3+ triggers a major oxidative unbalance in Escherichia coli, characterized by decreased intracellular thiol levels, increased superoxide concentration, as well as by an augmented production of the antioxidant enzymes superoxide dismutase and catalase. Because ROS production is, in some cases, associated with metal reduction and the concomitant generation of gold-containing nanostructures (AuNS), this possibility was evaluated in vivo and in vitro. Au3+ is toxic for E. coli because it triggers an unbalance of the bacterium’s oxidative status. This was demonstrated by using oxidative stress dyes and antioxidant chemicals as well as gene reporters, RSH concentrations and AuNS generation.

中文翻译：

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了解有氧生长的大肠杆菌中的金毒性。

有一个新兴领域可以付诸实践以开发具有抗菌特性的分子的新策略。在这一方面，几种金属和准金属目前正用于这些目的，尽管它们在特定生物中的细胞作用或靶标仍然未知。在这里，我们旨在通过生物化学和分子方法相结合的方法来调查和分析Au3 +的毒性。我们发现Au3 +在大肠杆菌中触发了主要的氧化不平衡，其特征是细胞内硫醇水平降低，超氧化物浓度升高以及抗氧化酶超氧化物歧化酶和过氧化氢酶的产量增加。由于在某些情况下，ROS的产生与金属的还原以及随之产生的含金纳米结构（AuNS）有关，在体内和体外评估了这种可能性。Au3 +对大肠杆菌有毒，因为它触发了细菌氧化状态的不平衡。通过使用氧化应激染料和抗氧化剂化学物质以及基因报告基因，RSH浓度和AuNS生成，可以证明这一点。