The spread of antibiotic-resistant bacteria and the rise of emerging and re-emerging viruses in recent years constitute significant public health problems. Therefore, it is necessary to develop new antimicrobial strategies to overcome these challenges. Herein, we describe an innovative method to synthesize ligand-free silver nanoparticles by Pulsed Laser Ablation in Liquid (PLAL-AgNPs). Thus produced, nanoparticles were characterized by total X-ray fluorescence, zeta potential analysis, transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate the nanoparticles’ cytotoxicity. Their potential was evaluated against the enveloped herpes simplex virus type 1 (HSV-1) and the naked poliovirus type 1 (PV-1) by plaque reduction assays and confirmed by real-time PCR and fluorescence microscopy, showing that nanoparticles interfered with the early stage of infection. Their action was also examined against different bacteria. We observed that the PLAL-AgNPs exerted a strong effect against both methicillin-resistant Staphylococcus aureus (S. aureus MRSA) and Escherichia coli (E. coli) producing extended-spectrum β-lactamase (ESBL). In detail, the PLAL-AgNPs exhibited a bacteriostatic action against S. aureus and a bactericidal activity against E. coli. Finally, we proved that the PLAL-AgNPs were able to inhibit/degrade the biofilm of S. aureus and E. coli.

中文翻译：

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无配体银纳米粒子：对抗病毒和细菌的创新策略

近年来，抗生素耐药细菌的传播以及新出现和重新出现的病毒的增加构成了重大的公共卫生问题。因此，有必要开发新的抗菌策略来克服这些挑战。在此，我们描述了一种通过液体中脉冲激光烧蚀合成无配体银纳米粒子（PLAL-AgNPs）的创新方法。通过总 X 射线荧光、zeta 电位分析、透射电子显微镜 (TEM) 和纳米颗粒跟踪分析 (NTA) 来表征由此产生的纳米颗粒。进行3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四唑(MTT)测定来评估纳米粒子的细胞毒性。通过噬菌斑减少试验评估了它们针对包膜单纯疱疹病毒 1 型 (HSV-1) 和裸脊髓灰质炎病毒 1 型 (PV-1) 的潜力，并通过实时 PCR 和荧光显微镜证实，表明纳米粒子干扰了早期感染阶段。还检查了它们对不同细菌的作用。我们观察到PLAL-AgNPs对耐甲氧西林金黄色葡萄球菌（S. aureus MRSA）和产生超广谱β-内酰胺酶（ESBL）的大肠杆菌（E. coli）具有很强的作用。具体而言，PLAL-AgNPs表现出对金黄色葡萄球菌的抑菌作用和对大肠杆菌的杀菌活性。最后，我们证明PLAL-AgNPs能够抑制/降解金黄色葡萄球菌和大肠杆菌的生物膜。