Data Sheet 1_Antibacterial, antifungal, and antibiofilm activities of biogenic zinc nanoparticles against pathogenic microorganisms.pdf

IntroductionThe increasing resistance to antimicrobial drugs has prompted global efforts to combat pathogenic bacteria and fungi. The World Health Organization’s recent report underscores the urgent need for innovative antimicrobial strategies to address infections caused by Staphylococcus aureus, Escherichia coli, Candida albicans, and Candida tropicalis. This study presents a comparative evaluation of the effects of biogenically synthesized zinc nanoparticles (ZnNPs) from Pseudomonas aeruginosa, highlighting their effectiveness against both planktonic and sessile forms of these tested pathogens.
MethodsThe antimicrobial effects were assessed using the Kirby-Bauer disk diffusion method, broth microdilution, and time-kill assays. Biofilm formation and eradication were evaluated through crystal violet staining, resazurin assays, and colony-forming unit quantification. Additionally, the oxidative and nitrosative stress toxicity mechanisms triggered by ZnNPs, particularly those related to cellular stress, were investigated.
ResultsThe results demonstrated that ZnNPs exhibit concentration-dependent inhibitory effects on both prokaryotic and eukaryotic microorganisms. ZnNPs inhibit biofilm formation by up to 50% in E. coli and yeast species, and up to 80% in S. aureus.
DiscussionThese antibiofilm activities were attributed to disruptions in cellular stress metabolism, primarily driven by nitrosative stress through enhanced production of reactive nitrogen intermediates. ZnNPs synthesized through green methods offer significant advantages due to their biocompatibility and potential biomedical applications. These findings advance our understanding of ZnNPs in combating biofilm-associated infections, offering promising strategies to address pathogenic bacteria and fungi, which pose a critical threat to global health.

引言
随着抗菌药物耐药性问题日益凸显，全球范围内已掀起对抗病原菌与真菌的研究热潮。世界卫生组织（World Health Organization）近期发布的报告强调，亟需开发创新型抗菌策略，以应对由金黄色葡萄球菌（Staphylococcus aureus）、大肠埃希菌（Escherichia coli）、白色念珠菌（Candida albicans）及热带念珠菌（Candida tropicalis）引发的感染。本研究对铜绿假单胞菌（Pseudomonas aeruginosa）生物合成的锌纳米颗粒（zinc nanoparticles, ZnNPs）的抗菌效果开展对比评价，重点阐明其对上述受试病原菌浮游态与固着态形式的抑制活性。

方法
本研究采用柯比-鲍尔纸片扩散法（Kirby-Bauer disk diffusion method）、肉汤微量稀释法（broth microdilution）及时间杀菌试验（time-kill assays）评估ZnNPs的抗菌活性。通过结晶紫染色（crystal violet staining）、刃天青试验（resazurin assays）及菌落形成单位计数（colony-forming unit quantification）评估生物膜的形成与清除效果。此外，本研究还探究了ZnNPs引发的氧化应激与亚硝化应激毒性机制，尤其是与细胞应激相关的通路。

结果
结果显示，ZnNPs对原核与真核微生物均表现出浓度依赖性的抑制作用。ZnNPs可使大肠埃希菌与酵母菌的生物膜形成量最高降低50%，对金黄色葡萄球菌的生物膜形成抑制率可达80%。

讨论
上述抗生物膜活性可归因于细胞应激代谢的紊乱，主要由亚硝化应激介导，通过增强活性氮中间体（reactive nitrogen intermediates）的生成实现。通过绿色方法合成的ZnNPs因具备良好的生物相容性与潜在的生物医学应用价值，具有显著优势。本研究结果加深了人们对ZnNPs对抗生物膜相关感染的认知，为应对对全球健康构成严重威胁的病原菌与真菌感染提供了极具前景的解决方案。