血啉甲醚对单增李斯特菌的光动力灭活作用及机理

Mechanisms of Anti-microbial Photodynamic Technology Against Listeria monocytogenes by Hematoporyrin Monomethyl Ether

通过平板菌落计数法研究血啉甲醚对单增李斯特菌的光动力灭活作用,同时采用聚丙烯酰胺凝胶电泳和聚合酶链式反应分析光动力灭菌技术对单增李斯特菌蛋白降解效果和基因组DNA的损伤程度。实验发现浓度为25μg/mL的血啉甲醚在光功密度为200 mW/cm2的溴钨灯光照射30 m in杀灭了99.9999%的单增李斯特菌,并导致了其蛋白质降解和基因组DNA片段断裂。血啉甲醚对单增李斯特菌的光动力灭活作用非常显著,其灭活机理可能是通过对蛋白质降解和基因组DNA损伤实现的。

Anti-microbial photodynamic technology （APDT） on L. monocytogenes was conducted using photo sen- sitizer hematoporyrin monomethyl ether （ HMME ） followed by tungsten-halogen lamp （ power density 200 mW/cm2 ）. The bactericidal effects were measured by counting the reduction of colony forming unit （ CFU ） after APDT-HMME treatment. The degradation of protein was observed under sodium dodeeyl sulphate polyacrylamide gel eleetrophoresis （SDS-PAGE）, and the damage of DNA was investigated by polymerase chain reaction （PCR）. Approximately 99. 9999% of L. monocytogenes were photo inactivated by illumination with 30 rain visible light in the presence of 25 μg/mL HMME. The cell killing effect to L. monocytogenes with illumination was much greater than in the dark at the same concentration of HMME. The protein of L. monocytogeneirradiated with HMME and visible light for 30 min was degraded obviously shown by SDS-PAGE graph and the DNA damage shown by＇ PCR graph was greater in APDT-treated groups compared with the control groups. The significant cell killing effect of APDT-HMME on L. monocytogenes may be explained by the bactericidal mechanism through the degradation of the protein and the damage of DNA.