Department of Microbiology, Lahijan Branch, Islamic Azad University, Lahijan, Iran.
Department of Biology, University of Guilan, Rasht, Iran.
World J Microbiol Biotechnol. 2022 Aug 30;38(11):209. doi: 10.1007/s11274-022-03384-4.
Biofilm formation and quorum sensing (QS) dependent virulence factors are considered the major causes of the emergence of drug resistance, therapeutic failure and development of Pseudomonas aeruginosa infections. This study aimed to investigate the effects of samarium oxide nanoparticles (SmONPs) on biofilm, virulence factors, and motility of multidrug-resistant P. aeruginosa. SmONPs were synthesized using curcumin and characterized by Transmission Electron Microscopy, X-ray diffractometer, Field Emission Scanning Electron Microscopy, and Energy-dispersive X-ray spectroscopy. Minimum inhibitory concentration (MIC) was determined using broth microdilution method. The antibiofilm potential of SmONPs was also evaluated by crystal violet staining and light microscopy examination. Then, the effect of sub-MICs concentrations of SmONPs on the proteolytic and hemolytic activities of P. aeruginosa was investigated. Finally, the effect of SmONPs on various types of motility including swarming, swimming, and twitching was studied. Our results showed that SmONPs significantly inhibited biofilm formation of P. aeruginosa by 49-61%. Additionally, sub-MICs concentrations of SmONPs effectively decreased virulence factors including pyocyanin (33-55%), protease (24-45%), and hemolytic activity (22-41%). Moreover, swarming, swimming, and twitching motility remarkably was reduced after exposure to the NPs. The findings of this work showed that SmONPs have a high potential in inhibiting QS-dependent virulence of P. aeruginosa, which could be considered for antibacterial chemotherapy after further characterization.
生物膜形成和群体感应（QS）依赖性毒力因子被认为是导致耐药性出现、治疗失败和铜绿假单胞菌感染发展的主要原因。本研究旨在探讨氧化钐纳米粒子（SmONPs）对多药耐药铜绿假单胞菌生物膜、毒力因子和运动性的影响。SmONPs 是使用姜黄素合成的，并通过透射电子显微镜、X 射线衍射仪、场发射扫描电子显微镜和能谱进行了表征。使用肉汤微量稀释法测定最小抑菌浓度（MIC）。还通过结晶紫染色和荧光显微镜检查评估了 SmONPs 的抗生物膜潜力。然后，研究了亚 MICs 浓度的 SmONPs 对铜绿假单胞菌蛋白水解和溶血活性的影响。最后，研究了 SmONPs 对各种类型运动性（包括群集、游泳和蠕动）的影响。我们的结果表明，SmONPs 可显著抑制铜绿假单胞菌生物膜形成，抑制率为 49-61%。此外，SmONPs 的亚 MICs 浓度可有效降低毒力因子，包括绿脓菌素（33-55%）、蛋白酶（24-45%）和溶血活性（22-41%）。此外，暴露于 NPs 后，群集、游泳和蠕动运动性明显降低。这项工作的结果表明，SmONPs 具有抑制 QS 依赖性铜绿假单胞菌毒力的巨大潜力，在进一步表征后可考虑用于抗菌化疗。
