Liu Shupei, Mai Bingjie, Jia Mengqi, Lin Dewu, Zhang Jingdan, Liu Quanhong, Wang Pan
National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
Photodiagnosis Photodyn Ther. 2020 Jun;30:101703. doi: 10.1016/j.pdpdt.2020.101703. Epub 2020 Mar 6.
Bacterial resistance to antibiotics is generally increasing, which has become a great challenge for treating infectious diseases caused by microbes. Photodynamic antibacterial chemotherapy (PACT) has been considered as a promising method for inactivating bacteria. The combination of antimicrobial agent with PACT may provide efficient way against drug-resistant microbe. This study aims to investigate the synergistic effects of PACT mediated by toluidine blue (TB), combined with gentamicin (GEN) on common pathogens Staphylococcus aureus (S. aureus) and multidrug-resistant S. aureus (MDR S. aureus).
Alkaline lysis was used to detect the uptake of TB by S. aureus and MDR S. aureus. Plate counting was applied to evaluate the inhibition efficiency of GEN alone, TB-PACT alone, and work together. Flow cytometry and fluorescence microscopy were performed to examine the permeability of bacterial membranes after different treatments. Intracellular and extracellular reactive oxygen species (ROS) were assessed with the assist of HDCF-DA and SOSG probes.
TB-PACT combined with GEN led to more pronounced antibacterial effects in S. aureus and MDR S. aureus, as compared with either alone. TB-PACT treatment permeabilized the bacterial membranes, promoted GEN cellular accumulation and augmented the antibacterial efficiency. The intracellular ROS generation by the combination of TB-PACT and GEN was much higher than that of single treatment groups.
TB-PACT decreased the GEN cytotoxic threshold and usage, and the synergy of them significantly enhanced the sterilization of S. aureus and MDR S. aureus.
细菌对抗生素的耐药性普遍增加，这已成为治疗由微生物引起的传染病的巨大挑战。光动力抗菌化疗（PACT）被认为是一种有前景的细菌灭活方法。抗菌剂与PACT的联合使用可能为对抗耐药微生物提供有效途径。本研究旨在探讨甲苯胺蓝（TB）介导的PACT联合庆大霉素（GEN）对常见病原体金黄色葡萄球菌（S. aureus）和多重耐药金黄色葡萄球菌（MDR S. aureus）的协同作用。
采用碱性裂解法检测金黄色葡萄球菌和多重耐药金黄色葡萄球菌对TB的摄取。采用平板计数法评估单独使用GEN、单独使用TB-PACT以及联合使用时的抑制效率。进行流式细胞术和荧光显微镜检查以检测不同处理后细菌膜的通透性。借助HDCF-DA和SOSG探针评估细胞内和细胞外活性氧（ROS）。
与单独使用相比，TB-PACT联合GEN对金黄色葡萄球菌和多重耐药金黄色葡萄球菌具有更显著的抗菌效果。TB-PACT处理使细菌膜通透性增加，促进GEN在细胞内的积累并提高抗菌效率。TB-PACT与GEN联合使用产生的细胞内ROS远高于单一处理组。
TB-PACT降低了GEN的细胞毒性阈值和用量，二者的协同作用显著增强了对金黄色葡萄球菌和多重耐药金黄色葡萄球菌的杀菌效果。
