Lourenço Cláudio, Macdonald Thomas J, Gavriilidis Asterios, Allan Elaine, MacRobert Alexander J, Parkin Ivan P
Materials Chemistry Research Centre, Department of Chemistry, University College London 20 Gordon St London WC1H 0AJ UK
Department of Chemical Engineering, University College London Torrington Place London, WC1E 7JE UK.
RSC Adv. 2018 Oct 5;8(60):34252-34258. doi: 10.1039/c8ra04361b. eCollection 2018 Oct 4.
Bovine serum albumin (BSA) is currently recommended as an interfering substance to emulate organic soiling, in evaluating the efficacy of disinfectants. The European Standard recommends 0.03% BSA to test clean conditions and 0.3% for dirty conditions. Reactive oxygen species are known to exert excellent antimicrobial activity with low specificity against a broad range of pathogens. Herein, we present our data from the first study of the effects of the addition of BSA on the antibacterial activity of light activated antimicrobial surfaces. Light activated antimicrobial surfaces were made from polyurethane swell-encapsulated with gold nanoparticles (AuNPs) coated with the light active triarylmethane dye, crystal violet (PU-AuNP-CV). The antibacterial efficacy of the antimicrobial substrates was tested against two strains of 8325-4, a well-characterised laboratory strain and MRSA 4742, a recent clinical isolate, in the presence of 0.1% to 1% BSA by irradiating the substrates with a fluorescent lamp (300 lux). After 6 hours of irradiation, the number of surviving bacteria was determined. The results showed that BSA reduced the antibacterial efficacy of all the PU-AuNP-CV surfaces with increasing BSA concentrations resulting in a progressive reduction in antibacterial activity towards the bacteria tested. However, the light activated surfaces did perform well at 0.1 and 0.25% BSA levels, showing they may have potential for real world environments with low levels of organic soiling.
在评估消毒剂的功效时，目前推荐使用牛血清白蛋白（BSA）作为一种干扰物质来模拟有机污垢。欧洲标准建议在测试清洁条件时使用0.03%的BSA，在测试脏污条件时使用0.3%的BSA。已知活性氧对多种病原体具有优异的抗菌活性，且特异性较低。在此，我们展示了第一项关于添加BSA对光活化抗菌表面抗菌活性影响的研究数据。光活化抗菌表面由聚氨酯制成，其膨胀封装有涂覆了光活性三芳基甲烷染料结晶紫（PU-AuNP-CV）的金纳米颗粒（AuNPs）。通过用荧光灯（300勒克斯）照射这些底物，在存在0.1%至1% BSA的情况下，测试了抗菌底物对两种菌株（一种是特征明确的实验室菌株8325-4，另一种是近期临床分离株MRSA 4742）的抗菌效果。照射6小时后，测定存活细菌的数量。结果表明，随着BSA浓度的增加，BSA降低了所有PU-AuNP-CV表面的抗菌效果，导致对所测试细菌的抗菌活性逐渐降低。然而，在0.1%和0.25%的BSA水平下，光活化表面表现良好，表明它们在低水平有机污垢的实际环境中可能具有潜力。
