该研究探究了405-nm LED （light-emitting diode）对不锈钢片表面金黄色葡萄球菌生物被膜的清除作用。首先测定了405-nm LED对不锈钢表面金黄色葡萄球菌生物被膜中活菌的灭活效果，随后通过分析405-nm LED处理后金黄色葡萄球菌生物被膜对消毒剂的耐受性、生物被膜化学成分以及生物被膜微观结构的变化研究405-nm LED对不锈钢表面金黄色葡萄球菌生物被膜可能的清除机理。结果表明，405-nm LED处理能够显著降低生物被膜内的活菌量：在4、10和25 ℃下使用LED处理4 h后，活菌量与对照组相比分别降低了2.03、2.08和3.00 log CFU/cm2；405-nm LED处理还降低了处理后的生物被膜细胞对消毒剂的耐受性；破坏了生物被膜立体构象的完整性和立体结构；降低了生物被膜主要组分的含量（胞外多糖和胞外蛋白质）。以上研究结果表明，405-nm LED可以有效清除不锈钢片表面的金黄色葡萄球菌生物被膜，其有潜力进一步开发作为新型生物被膜清除方法用于控制金黄色葡萄球菌生物被膜的污染。

In this study, the effect of a 405-nm light-emitting diode (LED) on the removal of the Staphylococcus aureus (S. aureus) biofilm formed on the surface of stainless steel was investigated. Firstly, the inactivation effect of 405-nm LED illumination on the viable cells in the S. aureus biofilm formed on stainless steel was determined. Then, the possible mechanisms underlying the biofilm clearance effects of LED were investigated through analyzing the resistance of S. aureus biofilm to disinfectants, chemical composition of the biofilm and the changes in the microstructure of biofilms after the 405-nm LED treatment. Results showed that the 405-nm LED treatment could significantly reduce the number of viable biofilm cells: The 4 h LED treatment at 4 ℃, 10 ℃ and 25 ℃ led to decreases in viable cells in the biofilm by 2.03 log CFU/cm2, 2.08 log CFU/cm2 and 3.00 log CFU/cm2, respectively, compared with the control group; the 405-nm LED treatment also decreased the tolerance of the treated biofilm cells to disinfectants, destroyed the integrity and three-dimensional structure of the biofilm's stereoscopic conformation, and reduced the contents of the main components of the biofilm (extracellular polysaccharides and extracellular proteins). The above research results indicated that the 405-nm LED illumination could effectively clear the S. aureus biofilm on the surface of stainless steel sheets, and has the potential to be further developed as a new biofilm removal method for the control of S. aureus biofilm contamination. Key words:

陕西省重点研发计划项目（2019NY-118）；陕西省博士后科研项目资助（2018BSHEDZZ150）；国家自然科学基金青年科学基金项目（31801659）