Department of Microbiology, Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland.
Trzebiatowski Institute of Low Temperature and Structure Research PAS in Wrocław, Wroclaw, Poland.
Int J Nanomedicine. 2020 Jan 14;15:199-213. doi: 10.2147/IJN.S208838. eCollection 2020.
Resistance to antibiotics is a major problem of public health. One of the alternative therapies is silver - more and more popular because of nanotechnology development and new possibilities of usage. As a component of colloid, powder, cream, bandages, etc., nanosilver is often recommended to treat the multidrug-resistant pathogens and we can observe its overuse also outside of the clinic where different physicochemical forms of silver nanoformulations (e.g. size, shape, compounds, surface area) are introduced. In this research, we described the consequences of long-term bacteria exposure to silver nanoformulations with different physicochemical properties, including changes in genome and changes of bacterial sensitivity to silver nanoformulations and/or antibiotics. Moreover, the prevalence of exogenous resistance to silver among multidrug-resistant bacteria was determined.
Gram-negative and Gram-positive bacteria strains are described as sensitive and multidrug-resistant strains. The sensitivity of the tested bacterial strains to antibiotics was carried out with disc diffusion methods. The sensitivity of bacteria to silver nanoformulations and development of bacterial resistance to silver nanoformulations has been verified via determination of the minimal inhibitory concentrations. The presence of genes was verified via PCR reaction and DNA electrophoresis. The genomic and phenotypic changes have been verified via genome sequencing and bioinformatics analysis.
Bacteria after long-term exposure to silver nanoformulations may change their sensitivity to silver forms and/or antibiotics, depending on the physicochemical properties of silver nanoformulations, resulting from phenotypic or genetic changes in the bacterial cell. Finally, adaptants and mutants may become more sensitive or resistant to some antibiotics than wild types.
Application of silver nanoformulations in the case of multiple resistance or multidrug-resistant bacterial infection can enhance or decrease their resistance to antibiotics. The usage of nanosilver in a clinic and outside of the clinic should be determined and should be under strong control. Moreover, each silver nanomaterial should be considered as a separate agent with a potential different mode of antibacterial action.
抗生素耐药性是公共卫生的主要问题之一。替代疗法之一是银 - 由于纳米技术的发展和新的应用可能性，越来越受欢迎。作为胶体、粉末、乳膏、绷带等的组成部分，纳米银经常被推荐用于治疗多药耐药病原体，而且我们也可以观察到它在临床之外的过度使用，在那里引入了不同的物理化学形式的银纳米制剂（例如，尺寸、形状、化合物、表面积）。在这项研究中，我们描述了具有不同物理化学性质的银纳米制剂长期暴露于细菌后的后果，包括基因组的变化以及细菌对银纳米制剂和/或抗生素的敏感性变化。此外，还确定了多药耐药细菌中外源对银的耐药性的流行情况。
革兰氏阴性和革兰氏阳性细菌菌株被描述为敏感和多药耐药菌株。用圆盘扩散法测定了测试细菌菌株对抗生素的敏感性。通过测定最小抑菌浓度来验证细菌对银纳米制剂的敏感性和细菌对银纳米制剂的耐药性发展。通过 PCR 反应和 DNA 电泳验证了 基因的存在。通过基因组测序和生物信息学分析验证了基因组和表型变化。
细菌经过长期暴露于银纳米制剂后，可能会根据银纳米制剂的物理化学性质，通过细菌细胞的表型或遗传变化，改变其对银的形态和/或抗生素的敏感性。最终，适应体和突变体可能比野生型对某些抗生素更敏感或耐药。
在多重耐药或多药耐药细菌感染的情况下应用银纳米制剂可以增强或降低其对抗生素的耐药性。纳米银在临床和临床外的应用应加以确定，并应受到严格控制。此外，应该将每种纳米银材料视为具有潜在不同抗菌作用模式的单独制剂。
