School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China.
China National Demonstration Center for Experimental Chemistry, Wuhan University, Wuhan 430072, China.
Environ Pollut. 2021 Jan 15;269:116138. doi: 10.1016/j.envpol.2020.116138. Epub 2020 Dec 2.
Noble metal-based nanomaterials (NMNs), such as platinum nanoparticles (Pt@NPs) and palladium nanoparticles (Pd@NPs), are increasingly being used as antibacterial agents. However, little information is available on bacterial resistance to NMNs. In this study, owing to their oxidase-like and peroxidase-like properties, both Pt@NPs and Pd@NPs induce reactive oxygen species (ROS) and manifest antibacterial activities: 6.25 μg/mL of either Pt@NPs or Pd@NPs killed >50% of Staphylococcus aureus strain ATCC29213. However, Pseudomonas aeruginosa strain PAO1 completely resisted 12.5 μg/mL of Pt@NPs and 6.25 μg/mL of Pd@NPs. Compared to the non-NMN groups, these NMNs promoted 2-3-fold upregulation of the quorum sensing (QS) gene lasR in strain PAO1. In fact, the lasR gene upregulation induced a 1.5-fold reduction in ROS production and increased biofilm formation by 11% (Pt@NPs) and 27% (Pd@NPs) in strain PAO1. The ΔlasR mutants (lasR gene knock out in strain PAO1), became sensitive to NMNs. The survival rates of ΔlasR mutants at 12.5 μg/mL Pt@NPs and Pd@NPs treatments were only 77% and 58%, respectively. This is the first report indicating that bacteria can resist NMNs through QS. Based on these results, evaluation of the ecological risks of using NMNs as antibacterial agents is necessary.
贵金属纳米材料（NMNs），如铂纳米粒子（Pt@NPs）和钯纳米粒子（Pd@NPs），越来越多地被用作抗菌剂。然而，关于细菌对 NMNs 的耐药性的信息很少。在这项研究中，由于其氧化酶和过氧化物酶样特性，Pt@NPs 和 Pd@NPs 均诱导活性氧物种（ROS）并表现出抗菌活性：6.25μg/mL 的 Pt@NPs 或 Pd@NPs 可杀死>50%的金黄色葡萄球菌 ATCC29213。然而，铜绿假单胞菌 PAO1 完全抵抗 12.5μg/mL 的 Pt@NPs 和 6.25μg/mL 的 Pd@NPs。与非 NMN 组相比，这些 NMNs 促进了铜绿假单胞菌 PAO1 中群体感应（QS）基因 lasR 的 2-3 倍上调。事实上，lasR 基因上调导致 ROS 产生减少 1.5 倍，并使铜绿假单胞菌 PAO1 的生物膜形成分别增加 11%（Pt@NPs）和 27%（Pd@NPs）。ΔlasR 突变体（铜绿假单胞菌 PAO1 中的 lasR 基因敲除）对 NMNs 敏感。ΔlasR 突变体在 12.5μg/mL Pt@NPs 和 Pd@NPs 处理下的存活率分别仅为 77%和 58%。这是第一个表明细菌可以通过 QS 抵抗 NMNs 的报告。基于这些结果，有必要评估将 NMNs 用作抗菌剂的生态风险。
