光动力作用对铜绿假单胞杆菌杀伤效应的研究

目的:探讨不同的光动力剂量下光动力疗法(photodynam ic therapy,PDT)对体外培养的铜绿假单胞杆菌的杀伤效应。方法:以耐药性较强的铜绿假单胞杆菌(Pseudom onas aeruginos,P.aeruginosa)为研究对象,采用亚甲基蓝(m ethylene b lue,MB)作为光敏剂,用656 nm的激光作为光源(m axoutput=300 mW),对不同系列浓度的MB进行不同剂量的光照,用菌落计数的办法来观测PDT对铜绿假单胞杆菌的杀伤作用;同时利用血培养基检测铜绿假单胞杆菌致病性的改变。结果:在光照剂量相同的情况下,浓度适中(131.7 m ol)的亚甲基蓝溶液能够有效地杀伤铜绿假单胞杆菌,使其致病性降低;而浓度较高(1 317 m ol)或较低(13.17 m ol)的亚甲基蓝溶液对铜绿假单胞杆菌的杀伤作用相对较弱。结论:光动力作用对体外培养的铜绿假单胞杆菌具有明确的杀伤作用,但是其效果和剂量关系密切,所以在治疗过程中必须寻找合适的光敏剂剂量。

Studies on Photodynamic Effects of MB on Pseudomonas aeruginosa in vitro

Objective:To examine the effects of photodynamic therapy(PDT) on pseudomonas aeruginos strain in vitro.Methods:The pseudomonas aeruginos strain is used to investigate the photodynamic efficacy of PDT,methylene blue(MB) be the photosensitizer and laser be the light source(max_(output)=300 mW).The cultured bacterium is treated with different concentrations of MB under different laser irradiation dosages.The bacteria groups were counted to measure the relative bacteria inhibitory rate introduced by PDT.In addition,the rabbit blood agar is used to detect the changes of nosogenesis to Pseudomonas aeuginosa strain.Results:With same light dose condition,the photodynamic efficacy and a reduced nosogenesis on Pseudomonas aeruginosa strain are most notable given proper concentration(131.7 mol) for methylene blue solution,while higher(1 317 mol) or lower(13.17 mol) concentration level does not present obvious results. Conclusions:PDT has significant photodynamic efficacy on Pseudomonas aeruginosa strain in vitro,its relative inhibitory rate presents close correlation with the dose of sensitizer and light irradiation.Hence discovering proper photosensitizer concentration during therapy is highly important.