Rapid evolution of silver nanoparticle resistance in Escherichia coli.
Rapid evolution of silver nanoparticle resistance in Escherichia coli.
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DOI：
10.3389/fgene.2015.00042
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发表时间：
2015
影响因子：
3.7
通讯作者：
Barrick JE
中科院分区：
文献类型：
--
作者：
Graves JL Jr;Tajkarimi M;Cunningham Q;Campbell A;Nonga H;Harrison SH;Barrick JE
最近工程纳米颗粒（eNPs）的使用呈指数增长意味着eNPs有意和无意地暴露于微生物。有意使用包括使用eNPs作为杀生物剂。非故意的暴露是由于eNPs被包含在各种商业产品（油漆、防晒霜、化妆品）中的事实。这些eNP中的许多由重金属或金属氧化物如银、金、锌、二氧化钛和氧化锌组成。据认为，由于金属/金属氧化物纳米颗粒影响细菌生理学的许多方面，因此细菌将难以对它们产生抗性。本研究利用实验室实验进化来进化大肠杆菌（K-12 MG 1655）中的银纳米颗粒（AgNP）抗性，大肠杆菌是一种不具有任何已知的银抗性元件的细菌。在暴露于AgNP环境的225代之后，处理群体表现出比对照菌株更大的适应性，如在不同浓度的10 nm柠檬酸盐涂覆的银纳米颗粒（AgNP）或硝酸银（AgNO 3）的存在下通过光密度（OD）和菌落形成单位（CFU）测量的。基因组分析表明，与AgNP抗性相关的变化已经在第100代的处理群体中积累，到第200代，三种突变在AgNP抗性种群中以高频率出现。这项研究表明，尽管以前的说法相反，细菌可以很容易地进化出对AgNP的抗性，这是通过相对简单的基因组变化发生的。这些结果表明，应注意使用eNP作为杀生物剂以及关于微生物群落无意暴露于废物中的eNP。
The recent exponential increase in the use of engineered nanoparticles (eNPs) means both greater intentional and unintentional exposure of eNPs to microbes. Intentional use includes the use of eNPs as biocides. Unintentional exposure results from the fact that eNPs are included in a variety of commercial products (paints, sunscreens, cosmetics). Many of these eNPs are composed of heavy metals or metal oxides such as silver, gold, zinc, titanium dioxide, and zinc oxide. It is thought that since metallic/metallic oxide NPs impact so many aspects of bacterial physiology that it will difficult for bacteria to evolve resistance to them. This study utilized laboratory experimental evolution to evolve silver nanoparticle (AgNP) resistance in the bacterium Escherichia coli (K-12 MG1655), a bacterium that does not harbor any known silver resistance elements. After 225 generations of exposure to the AgNP environment, the treatment populations demonstrated greater fitness vs. control strains as measured by optical density (OD) and colony forming units (CFU) in the presence of varying concentrations of 10 nm citrate-coated silver nanoparticles (AgNP) or silver nitrate (AgNO3). Genomic analysis shows that changes associated with AgNP resistance were already accumulating within the treatment populations by generation 100, and by generation 200 three mutations had swept to high frequency in the AgNP resistance stocks. This study indicates that despite previous claims to the contrary bacteria can easily evolve resistance to AgNPs, and this occurs by relatively simple genomic changes. These results indicate that care should be taken with regards to the use of eNPs as biocides as well as with regards to unintentional exposure of microbial communities to eNPs in waste products.