The uses of metallic nanoparticles have gained importance as one of the therapeutic options to treat infections. Here, we synthesized stable copper nanoparticles (CuNPs) using Thiosalicylic acid and assessed their antimicrobial activities against various Gram-negative bacteria. The synthesized CuNPs had absorption maxima of 570 nM with a size range of 5-11 nM and face-centred cubic (Fcc) crystal structure. The bacterial cells in their planktonic and sessile forms were susceptible to CuNPs. The nanoparticles did not show any cytotoxicity to murine macrophages (RAW264.7) below 60 µg/mL. However, the expression of oxidative stress defence gene ahpC revealed the possibility of ROS generation upon treatment with CuNPs. Interestingly, the cell division proteins like, FtsZ and FtsI were destabilized in the presence of CuNPs which in turn inhibited bacterial cell division. In conclusion, it may be stated that the synthesized CuNPs can kill bacteria by arresting cell division and/or by ROS generation.

中文翻译：

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硫醇稳定的铜纳米颗粒通过防止大肠杆菌中的细胞分裂发挥抗菌作用

金属纳米颗粒的用途作为治疗感染的治疗选择之一已变得越来越重要。在这里，我们使用硫代水杨酸合成了稳定的铜纳米颗粒（CuNPs），并评估了它们对各种革兰氏阴性细菌的抗菌活性。合成的CuNPs的最大吸收值为570 nM，尺寸范围为5-11 nM，具有面心立方（Fcc）晶体结构。浮游和无柄形式的细菌细胞对CuNP敏感。低于60 µg / mL的纳米颗粒对鼠巨噬细胞（RAW264.7）没有任何细胞毒性。然而，氧化应激防御基因ahpC的表达揭示了用CuNPs处理后产生ROS的可能性。有趣的是，细胞分裂蛋白例如 FtsZ和FtsI在存在CuNP的情况下不稳定，进而抑制细菌细胞分裂。总之，可以说合成的CuNP可以通过阻止细胞分裂和/或通过ROS产生来杀死细菌。