This study was conducted to evaluate the antibacterial effect of 460–470 nm light-emitting diodes illumination (460/470 LED) combined with various antimicrobials at inactivating Escherichia coli O157:H7 and identify the antibacterial mechanisms. When carvacrol, thymol, citric acid, malic acid, citrus fruit extract, 3% NaCl, or 5% NaCl was combined with 460/470 LED, there was a higher reduction in E. coli O157:H7 compared to 460/470 LED treatment or antimicrobials alone at 4 °C. Particularly, a marked synergistic effect (>8.74 log₁₀ CFU/ml) was observed when 460/470 LED was combined with carvacrol, malic acid, citrus fruit extract, or 3% NaCl. Levels of intracellular ROS and lipid peroxidation of E. coli O157:H7 were higher in the combination of 460/470 LED and antimicrobials compared to individual treatments. Moreover, the combination treatment increased depolarization of the cell membrane leading to membrane damage as well as the loss of DNA integrity. Thus, adding antimicrobial treatment to 460/470 LED could improve its efficacy against pathogenic bacteria such as E. coli O157:H7.

这项研究的目的是评估460-470 nm发光二极管照明（460/470 LED）与各种抗菌素的结合对灭活大肠杆菌O157：H7的抗菌作用，并确定其抗菌机制。当将香芹酚，百里香酚，柠檬酸，苹果酸，柑桔提取物，3％NaCl或5％NaCl与460/470 LED结合使用时，与460/470 LED处理相比，大肠杆菌O157：H7的减少量更高或仅在4°C下使用抗菌剂。特别地，当460/470 LED与香芹酚，苹果酸，柑橘类水果提取物或3％NaCl组合时，观察到显着的协同作用（> 8.74 log ₁₀ CFU / ml）。大肠杆菌的细胞内ROS水平和脂质过氧化与单独治疗相比，在460/470 LED和抗菌剂的组合中O157：H7更高。而且，联合治疗增加了细胞膜的去极化，导致膜损伤以及DNA完整性的损失。因此，在460/470 LED上添加抗菌处理可以提高其对病原菌（如大肠杆菌O157：H7）的功效。