Biosynthesized silver nanoparticles at subinhibitory concentrations as inhibitors of quorum sensing, pathogenicity, and biofilm formation in Pseudomonas aeruginosa PAO1

作者：F. Aflakian, G. Hashemitabar · 发表于：Heliyon · 年份：2025 · DOI：10.1016/j.heliyon.2025.e42899 · 被引用次数：19 · 研究领域：Medicine

Pseudomonas aeruginosa infections associated with biofilm are a significant clinical challenge due to the limited efficacy of traditional antibiotics or combination therapies. Hence, exploring novel strategies and assessing different compounds for their anti-biofilm or anti-quorum sensing (QS) properties is imperative. One of the various applications of silver nanoparticles (AgNPs) is to use them as an antimicrobial agent to target bacteria resistant to common antibiotics. This study evaluates the anti-biofilm and anti-virulence effect of biosynthesized AgNPs against P. aeruginosa PAO1 at subinhibitory concentration levels. Minimum inhibitory concentrations (MICs) and biofilm formation capacity were evaluated by the microdilution method and crystal violet method, respectively. Motility assay and virulence factors were investigated in the presence of AgNPs. It was observed that green-synthesized AgNPs at sub-MIC (50 μg/mL) suppressed P. aeruginosa biofilm formation by 78 %. Increased dose-dependent inhibitory effects on virulence phenotypes (LasB elastase, LasA protease, pyocyanin, and motility) regulated by QS were observed. In addition, the relative expression levels of biofilm-related genes including algC, pslA, and pelA were analyzed using RT-qPCR. The expression level of QS-regulated biofilm genes after AgNPs treatment sub-MIC led to a decrease in the expression of algC, pslA, and pelA by 77 %, 83 %, and 68 %, respectively. The findings of this study demonstrated how gree...