Contact Killing of Bacteria on Copper Is Suppressed if Bacterial-Metal Contact Is Prevented and Is Induced on Iron by Copper Ions
Contact Killing of Bacteria on Copper Is Suppressed if Bacterial-Metal Contact Is Prevented and Is Induced on Iron by Copper Ions
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DOI：
10.1128/aem.03608-12
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发表时间：
2013-04-01
影响因子：
4.4
通讯作者：
Solioz, Marc
中科院分区：
文献类型：
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作者：
Mathews, Salima;Hans, Michael;Solioz, Marc
细菌在铜表面被迅速杀灭，从铜表面释放出来的铜离子被认为在杀菌过程中起着主要作用。然而，目前尚不清楚细菌与铜表面的接触是否也是一个重要因素。使用激光干涉光刻，我们设计了覆盖有惰性聚合物网格的铜表面，以防止细菌与表面接触。以河野肠球菌为模型生物，我们发现这些修饰表面的离子铜的释放并没有明显的减少。相比之下，对细菌的杀灭作用明显减弱。当细胞暴露在固体铁表面时，细胞活力的损失与在玻璃上相同。然而，在4 mM CuSO4存在的情况下，将细胞暴露于铁可以在100分钟内完全杀死细胞。这些实验表明，接触杀死是通过一种机制进行的，即金属与细菌的接触破坏了细胞膜，这反过来又使细胞容易受到铜离子的进一步损害。
Bacteria are rapidly killed on copper surfaces, and copper ions released from the surface have been proposed to play a major role in the killing process. However, it has remained unclear whether contact of the bacteria with the copper surface is also an important factor. Using laser interference lithography, we engineered copper surfaces which were covered with a grid of an inert polymer which prevented contact of the bacteria with the surface. Using Enterococcus hirae as a model organism, we showed that the release of ionic copper from these modified surfaces was not significantly reduced. In contrast, killing of bacteria was strongly attenuated. When E. hirae cells were exposed to a solid iron surface, the loss of cell viability was the same as on glass. However, exposing cells to iron in the presence of 4 mM CuSO4 led to complete killing in 100 min. These experiments suggest that contact killing proceeds by a mechanism whereby the metal-bacterial contact damages the cell envelope, which, in turn, makes the cells susceptible to further damage by copper ions.