Antimicrobial Activity of Arthrospira platensis-Mediated Gold Nanoparticles against Streptococcus pneumoniae: A Metabolomic and Docking Study

作者：Lamya Azmy, Ebtesam Al‐Olayan, Mohamed Abdel‐Hamid, Ahmed Zayed, Saly F. Gheda, Khayrya A. Youssif, Hesham A. Abou‐Zied, Usama Ramadan Abdelmohsen, Ibraheem Ibraheem, Seung Pil Pack, Khaled N. M. Elsayed · 发表于：International Journal of Molecular Sciences · 年份：2024 · DOI：10.3390/ijms251810090 · 被引用次数：19 · 研究领域：Andrographolide Research and Applications、Computational Drug Discovery Methods

The emergence of antibiotic-resistant Streptococcus pneumoniae necessitates the discovery of novel therapeutic agents. This study investigated the antimicrobial potential of green-synthesized gold nanoparticles (AuNPs) fabricated using Arthrospira platensis extract. Characterization using Fourier transform infrared spectroscopy revealed the presence of functional groups such as ketones, aldehydes, and carboxylic acids in the capping agents, suggesting their role in AuNP stabilization. Transmission electron microscopy demonstrated the formation of rod-shaped AuNPs with a mean diameter of 134.8 nm, as determined by dynamic light scattering, and a zeta potential of −27.2 mV, indicating good colloidal stability. The synthesized AuNPs exhibited potent antibacterial activity against S. pneumoniae, with a minimum inhibitory concentration (MIC) of 12 μg/mL, surpassing the efficacy of the control antibiotic, tigecycline. To elucidate the underlying mechanisms of action, an untargeted metabolomic analysis of the A. platensis extract was performed, identifying 26 potential bioactive compounds belonging to diverse chemical classes. In silico studies focused on molecular docking simulations revealed that compound 22 exhibited a strong binding affinity to S. pneumoniae topoisomerase IV, a critical enzyme for bacterial DNA replication. Molecular dynamics simulations further validated the stability of this protein–ligand complex. These findings collectively highlight the promising antimicrob...