Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK.
J Appl Microbiol. 2010 Dec;109(6):2200-5. doi: 10.1111/j.1365-2672.2010.04852.x. Epub 2010 Oct 11.
Studies to date have shown rapid killing of bacterial cells when exposed to copper surfaces. The mechanistic action of copper on bacterial cells is so far unknown.
To investigate potential mechanisms involved, meticillin-resistant Staphylococcus aureus (MRSA) cells (10(7) CFU) were inoculated onto coupons of copper or stainless steel and stained with either the viability fluorophore 5-cyano-2,3-ditolyl tetrazolium (CTC), to detect respiration, or BacLight™ (SYTO9/propidium iodide), to determine cell wall integrity. Coupons were then observed in-situ using epifluorescence microscopy. In addition, DNA from cells inoculated onto either copper or stainless steel surfaces was isolated and analysed by agarose gel electrophoresis. An effect on cellular respiration with CTC reduction was evident but no effect on cell membrane integrity (BacLight™) was observed. Results from the DNA isolation indicated a copper-induced detrimental effect on MRSA genomic material as no bands were observed after exposure to copper surface.
The results indicate that exposure to copper surfaces rapidly kills MRSA by compromising cellular respiration and damaging DNA, with little effect on cell membrane integrity.
This research provides a mechanistic explanation in support of previous suggestions that although copper surfaces do not affect membrane integrity of cells, there is still a rapid antimicrobial effect.
迄今为止的研究表明，细菌细胞在暴露于铜表面时会迅速死亡。铜对细菌细胞的作用机制尚不清楚。
为了研究潜在的相关机制，将耐甲氧西林金黄色葡萄球菌（MRSA）细胞（10(7) CFU）接种到铜或不锈钢的小片中，并用呼吸荧光染料 5-氰基-2,3-二苯四唑（CTC）或 BacLight™（SYTO9/碘化丙啶）染色，以检测细胞呼吸或细胞壁完整性。然后使用荧光显微镜在原位观察小皿。此外，从接种到铜或不锈钢表面的细胞中分离 DNA，并通过琼脂糖凝胶电泳进行分析。用 CTC 减少法检测到细胞呼吸的明显影响，但用 BacLight™ 检测不到细胞膜完整性的影响。DNA 分离的结果表明，铜对 MRSA 基因组物质有不良影响，因为暴露于铜表面后没有观察到任何带。
结果表明，暴露于铜表面会通过损害细胞呼吸和 DNA 来迅速杀死 MRSA，而对细胞膜完整性的影响很小。
这项研究提供了一种机制解释，支持了以前的观点，即尽管铜表面不会影响细胞的膜完整性，但仍存在快速的抗菌作用。
