Silver nanoparticles (AgNP) have been widely applied because of their broad spectrum of antimicrobial activities against bacteria, fungi, and viruses. However, little research has been done to evaluate their effects on Cronobacter sakazakii, an opportunistic pathogen usually infecting infants and having a high fatality rate. The aims of this work were to investigate the antibacterial property of novel, synthesized, positively charged silver nanoparticles against C. sakazakii and to discuss the potential antibacterial mechanisms involved. In this study, the spherical and face-centered cubic silver nanoparticles had a mean particle size of 31.2 nm and were synthesized by reducing Ag⁺ using citrate and dispersed by glycerol and polyvinylpyrrolidone (PVP) under alkaline conditions. Minimum inhibitory concentrations (MIC) and inhibition zone tests showed that the AgNP exhibited strong antibacterial activity against 4 tested C. sakazakii strains with mean MIC of 62.5 to 125 mg/L and average inhibition zone diameters of 13.8 to 16.3 mm. Silver nanoparticles caused cell membrane injury accompanied by adsorption of AgNP onto the cell surface, as shown by changes in cell morphology, cell membrane hyperpolarization, and accelerated leakage of intracellular reducing sugars and proteins outward from the cytoplasm. In addition, dysfunction of the respiratory chain was induced after treatment with AgNP, which was supported by a decrease in intracellular ATP and inhibition of related dehydrogenases. This research indicates that AgNP could be a novel and efficient antibacterial agent to control C. sakazakii contamination in environments producing powdered infant formulas from milk.

银纳米颗粒（AgNP）由于其对细菌，真菌和病毒的广泛抗菌活性而被广泛应用。然而，很少有研究评估它们对阪崎肠杆菌的影响，阪崎肠杆菌是一种机会性病原体，通常会感染婴儿并且死亡率很高。这项工作的目的是调查新型，合成，带正电的银纳米粒子对阪崎肠杆菌的抗菌性能，并讨论涉及的潜在抗菌机制。在这项研究中，球形和面心立方银纳米颗粒的平均粒径为31.2 nm，是通过还原Ag ⁺使用柠檬酸盐，并在碱性条件下由甘油和聚乙烯吡咯烷酮（PVP）分散。最低抑菌浓度（MIC）和抑菌圈试验表明，AgNP对4种受试阪崎肠杆菌显示出强大的抗菌活性。菌株的平均MIC为62.5至125 mg / L，平均抑制区直径为13.8至16.3 mm。银纳米颗粒引起细胞膜损伤，伴随有AgNP吸附到细胞表面，如细胞形态的变化，细胞膜超极化和细胞内还原糖和蛋白质从细胞质向外加速泄漏所显示。另外，用AgNP治疗后，呼吸链功能障碍被诱导，这由细胞内ATP的减少和相关脱氢酶的抑制来支持。这项研究表明，AgNP可能是一种新型有效的抗菌剂，可在由牛奶生产婴儿配方奶粉的环境中控制阪崎肠杆菌的污染。