Photofrin联合碘化钾抗革兰阴性细菌光动力效果的研究

Study of photodynamic effect of Photofrin plus potassium iodide against Gram-negative bacteria

目的:探索碘化钾(KI)对Photofrin(PF)介导的抗菌光动力疗法(aPDT)抗革兰阴性细菌效果的影响。方法:以铜绿假单胞菌(P.a)、肺炎克雷伯菌(K.p)、奇异变形杆菌(P.m)和鲍曼不动杆菌(A.b)为实验对象,用不同浓度PF及KI进行光动力处理,观察并计算CFU及各组细菌存活率。用Amplex Red检测H2O2以探索KI提高PF介导的aPDT效果的机制。结果:当光能量密度为10 J/cm^(2)时,不同浓度的PF对这4种革兰阴性细菌均无杀伤效果。当光能量密度为10 J/cm^(2)时,50 mmol/L KI联合10μmol/L PF可对A.b实现高效杀菌(P<0.001);100 mmol/L KI联合10μmol/L PF可对P.a、K.p和P.m实现高效杀菌(P<0.001)。当光能量密度相同时,10μmol/L PF联合100 mmol/L KI组的荧光量明显高于对照组(P<0.05)。结论:PF联合KI对革兰阴性细菌的抗菌作用显著增强,其增强作用可能是由于^(1)O_(2)与KI反应生成H_(2)O_(2)。

Objective:To explore the effect of potassium iodide(KI)on antimicrobial photodynamic therapy(aP-DT)mediated by Photofrin(PF)against Gram-negative bacteria.Methods:Pseudomonas aeruginosa(P.a),Kleb-siella pneumoniae(K.p),Proteus mirabilis(P.m)and Acinetobacter baumannii(A.b)were used as experimental subjects.After photodynamic treatment with varying concentrations of PF and KI,the CFU and survival rate of bacteria in each group were observed and calculated.In order to investigate the mechanism by which KI in-creased the effect of PF-mediated aPDT,Amplex Red was utilized to detect H2O2.Results:For these four Gram-negative bacteria with varying PF concentrations,there was no bactericidal impact when the light energy density was 10 J/cm^(2).When the light energy density was 10 J/cm^(2),50 mmol/L KI combined with 10μmol/L PF could ef-fectively kill A.b bacteria(P<0.001)and the combination of 100 mmol/L KI and 10μmol/L PF could achieve high bactericidal effect against P.a,K.p and P.m(P<0.001).When the light energy density was the same,the flu-orescence amount of the 10μmol/L PF combined with 100 mmol/L KI group was significantly higher than that of the control group(P<0.05).Conclusion:The antibacterial effect of PF combined with KI against Gram-negative bacteria is significantly enhanced,and the enhanced effect may be due to the reaction of^(1)O_(2)with KI to generate H_(2)O_(2).