Ji Haiying, Dong Tingting, Liang Guochao, Xu Haijian, Wang Chunyan, Liu Tianjun, Hong Ge
Tangshan Maternal and Child Health Hospital, China.
Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, China.
Photodiagnosis Photodyn Ther. 2023 Dec;44:103857. doi: 10.1016/j.pdpdt.2023.103857. Epub 2023 Oct 27.
Pseudomonas aeruginosa is a gram-negative bacterium without spores, and it is one of the pathogens that easily cause secondary infectious diseases when human immune function is low. The purpose of this study is to explore the inhibitory effect of photodynamic antibacterial chemotherapy-induced by cationic porphyrin derivative on clinical P. aeruginosa and its mechanism.
The uptake of photosensitizer by P. aeruginosa and L929 cells was measured by an ultraviolet spectrophotometer. Effect of laser energy density on the bacterial activity of P. aeruginosa and post antibiotic effect were measured by bacterial suspension and tenfold dilution method. Flow cytometry and scanning electron microscopy were used to observe the activity and morphological changes of P. aeruginosa after PACT treatment.
The uptake of Tetra-ATPP-Lys-by P. aeruginosa and L929 was shown as concentration-dependent and time-dependent. However the uptake of L929 cell had a clear difference with P. aeruginosa at the same time and concentration intervals(P < 0.05).The increasing laser energy density had a high inactivation effect of on P. aeruginosa at the same Tetra-ATPP-Lys-concentration(P < 0.05). Post-antibiotic effect of Tetra-ATPP-Lys -PACT was dose-dependent(P < 0.05). Bacterial viability which evaluated by the flow cytometry method demonstrated that the proportion of viable bacteria is decreased with the photosensitizer dose-dependent. The morphology and microstructure of P. aeruginosa after Tetra-ATPP-Lys -PACT was demonstrated by a scanning electron microscope(SEM). After PACT, the morphology of P. aeruginosa was rod-shaped, the outer membrane surface was rough, and the bacteria were dry flat, sunken, shrunk and deformed.
Cationic porphyrin photosensitizer had a great damage effect on P. aeruginosa under the PACT, which can effectively destroy the microstructure of bacteria and lead to bacterial inactivation and death.
铜绿假单胞菌是一种无芽孢的革兰氏阴性菌，是人类免疫功能低下时易引发继发性感染疾病的病原体之一。本研究旨在探讨阳离子卟啉衍生物诱导的光动力抗菌化疗对临床分离的铜绿假单胞菌的抑制作用及其机制。
采用紫外分光光度计测定铜绿假单胞菌和L929细胞对光敏剂的摄取。采用细菌悬液和十倍稀释法测定激光能量密度对铜绿假单胞菌细菌活性的影响及抗生素后效应。采用流式细胞术和扫描电子显微镜观察光动力抗菌化疗（PACT）处理后铜绿假单胞菌的活性和形态变化。
铜绿假单胞菌和L929细胞对四氨基苯基卟啉赖氨酸（Tetra-ATPP-Lys）的摄取呈浓度和时间依赖性。然而，在相同的时间和浓度区间，L929细胞的摄取与铜绿假单胞菌有明显差异（P<0.05）。在相同的四氨基苯基卟啉赖氨酸（Tetra-ATPP-Lys）浓度下，增加激光能量密度对铜绿假单胞菌有较高的灭活作用（P<0.05）。四氨基苯基卟啉赖氨酸-光动力抗菌化疗（Tetra-ATPP-Lys-PACT）的抗生素后效应呈剂量依赖性（P<0.05）。通过流式细胞术方法评估的细菌活力表明，活菌比例随光敏剂剂量依赖性降低。扫描电子显微镜（SEM）显示了四氨基苯基卟啉赖氨酸-光动力抗菌化疗（Tetra-ATPP-Lys-PACT）后铜绿假单胞菌的形态和微观结构。光动力抗菌化疗（PACT）后铜绿假单胞菌呈杆状，外膜表面粗糙，菌体干瘪、凹陷、皱缩、变形。
阳离子卟啉光敏剂在光动力抗菌化疗（PACT）作用下对铜绿假单胞菌有较大损伤作用，可有效破坏细菌微观结构，导致细菌失活死亡。
