Azimzadeh Masoud, Greco Grazia, Farmani Abbas, Nourian Alireza, Pourhajibagher Maryam, Taherkhani Amir, Alikhani Mohammad Yousef, Bahador Abbas
Department of Microbiology, Hamadan University of Medical Sciences, Hamadan, Iran.
Department of Veterinary Medicine, University of Bari "Aldo Moro", Valenzano, Bari, 70010, Italy.
Sci Rep. 2025 Apr 29;15(1):14993. doi: 10.1038/s41598-025-00005-6.
We aimed to investigate the synergistic effects of colistin and green-synthesized silver nanoparticles on the biofilm formation and expression of Quorum Sensing regulated and related genes in clinical isolates of P. aeruginosa. Ten clinical P. aeruginosa isolates collected from patients with burn wound infections were investigated. The antibiotic sensitivity pattern of the isolates was determined using disk diffusion and microbroth dilution tests. The silver nanoparticles (AgNPs) were synthesized using propolis and characterized. The microtiter plate method and scanning electron microscopy (SEM) were used to evaluate the synergistic effects of colistin and silver nanoparticles combination (AgNPs@CL) on the inhibition of biofilm formation. The effect of AgNPs@CL on the expression of genes controlled by QS was evaluated using RT-PCR. All isolates were strong biofilm formers. Confronting AgNPs@CL, all isolates were either synergistic or additive and effectively decrease the minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC) values of Carbapenem-Resistant P. aeruginosa (CRPA) isolates. The SEM analysis corroborated the enhanced biofilm inhibition observed with the combined treatment compared to individual AgNPs or colistin treatments. When exposed to AgNPs@CL, the expression levels of lasI, lasR, rhlI, rhlR, pelA, and pslA genes significantly decreased in P. aeruginosa ATCC 27,853 and clinical isolate No. #354, which displayed synergistic activity. In contrast, with additive activity, clinical isolate No. #30 showed no significant decrease. Targeting critical components of QS could effectively inhibit biofilm production. The results of our study suggest AgNPs@CL as an auxiliary to antibiotic therapy.
我们旨在研究黏菌素与绿色合成银纳米颗粒对铜绿假单胞菌临床分离株生物膜形成以及群体感应调控和相关基因表达的协同作用。对从烧伤创面感染患者中收集的10株临床铜绿假单胞菌分离株进行了研究。使用纸片扩散法和微量肉汤稀释试验确定分离株的抗生素敏感性模式。用蜂胶合成银纳米颗粒（AgNPs）并进行表征。采用微量滴定板法和扫描电子显微镜（SEM）评估黏菌素与银纳米颗粒组合（AgNPs@CL）对生物膜形成的抑制协同作用。采用逆转录聚合酶链反应（RT-PCR）评估AgNPs@CL对群体感应控制基因表达的影响。所有分离株均为强生物膜形成菌。面对AgNPs@CL，所有分离株均表现出协同或相加作用，并有效降低了耐碳青霉烯铜绿假单胞菌（CRPA）分离株的最低抑菌浓度（MIC）和最低生物膜抑菌浓度（MBIC）值。SEM分析证实，与单独的AgNPs或黏菌素处理相比，联合处理观察到生物膜抑制作用增强。当暴露于AgNPs@CL时，铜绿假单胞菌ATCC 27853和具有协同活性的临床分离株#354中lasI、lasR、rhlI、rhlR、pelA和pslA基因的表达水平显著降低。相比之下，具有相加活性的临床分离株#30则没有显著降低。靶向群体感应的关键成分可有效抑制生物膜产生。我们的研究结果表明AgNPs@CL可作为抗生素治疗的辅助手段。
