Silver nanoparticles have already been successfully applied in various biomedical and antimicrobial technologies and products used in everyday life. Although bacterial resistance to antibiotics has been extensively discussed in the literature, the possible development of resistance to silver nanoparticles has not been fully explored. We report that the Gram-negative bacteria Escherichia coli 013, Pseudomonas aeruginosa CCM 3955 and E. coli CCM 3954 can develop resistance to silver nanoparticles after repeated exposure. The resistance stems from the production of the adhesive flagellum protein flagellin, which triggers the aggregation of the nanoparticles. This resistance evolves without any genetic changes; only phenotypic change is needed to reduce the nanoparticles’ colloidal stability and thus eliminate their antibacterial activity. The resistance mechanism cannot be overcome by additional stabilization of silver nanoparticles using surfactants or polymers. It is, however, strongly suppressed by inhibiting flagellin production with pomegranate rind extract.

银纳米颗粒已经成功应用于日常生活中使用的各种生物医学和抗菌技术和产品。尽管文献中已广泛讨论了细菌对抗生素的抗药性，但尚未充分探索对银纳米颗粒抗药性的可能发展。我们报告革兰氏阴性细菌大肠杆菌013，铜绿假单胞菌CCM 3955和大肠杆菌反复暴露后，CCM 3954可以产生对银纳米颗粒的抗性。耐药性源自粘附性鞭毛蛋白鞭毛蛋白的产生，其触发了纳米颗粒的聚集。这种抗性在没有任何遗传改变的情况下进化。仅需要改变表型即可降低纳米颗粒的胶体稳定性，从而消除其抗菌活性。通过使用表面活性剂或聚合物对银纳米颗粒进行额外的稳定化无法克服电阻机制。然而，通过抑制石榴皮提取物鞭毛蛋白的产生，可以强烈地抑制它。