应用激光共聚焦显微镜观察光动力技术对单增李斯特菌菌膜的灭活作用  

Using confocal laser scanning microscope visualizing the effect of anti-microbial photodynamic technology against Listeria monocytogenes biofilms

作　　者：李红爱[1] 胡慧丹 邓曦[1] 刘爽[1] 唐书泽[1] 吴希阳[1] 陈振强[3] 

机构地区：[1]暨南大学食品科学与工程系,广东广州510632 [2]广州皇上皇集团有限公司,广东广州510240 [3]暨南大学光电工程系,广东广州510632

出　　处：《食品工业科技》2014年第4期157-160,共4页Science and Technology of Food Industry

基　　金：广东省自然科学基金项目(S2012010008479);广东省突发公共事件应急技术研究中心专项([2011]733)

摘　　要：以亚甲基蓝(methylene blue,MB)为光敏剂,采用光催化专用氙灯光源(光功率密度为200mW/cm2),通过激光共聚焦扫描显微镜(confocal laser scanning microscope,CLSM)观察法探讨了光动力杀菌技术(anti-microbial photodynamic technology,APDT)对单增李斯特菌(Listeria monocytogenes,LM)菌膜(biofiLM,BF)的灭活作用。结果表明,MB-APDT处理的LM BF经过SYTO9/PI染色后在CLSM下观察,灭活效果区分明显。这一效果由平板菌落计数法得到进一步证实。光照20min,当MB的浓度低至0.1μg/mL时,APDT对于生长8h的BF失活率达到99.7%;当MB浓度为50μg/mL时,几乎全部LM BF失活。当MB浓度为1μg/mL时,光照5min即可使约99.6%生长8h的LM BF失活,也可使约78.7%生长36h的BF失活;当光照时间为30min时,生长8h LM-BF失活率达到99.97%,而生长36h BF失活率也达到99.94%。MB-APDT对LM BF的灭活效果主要取决于MB浓度和光照时间,且杀伤作用非常显著。The efficacy of anti-microbial photodynamic technology（APDT） against Listeria monocytogenes（LM） biofilm （BF） by methylene blue （MB） under photocatalysis -xenon lamp light （power density 200mW/cm2） was visualized using confocal laser scanning microscope （CLSM） and investigated by counting colony - forming units （CFU）. Obtained results indicated that the efficacy of MB -APDT to LM BF was clearly visual through CLSM based on SYT09/PI staining. In addition, standard plate counts of celis recovered from biofilms were used to quantify the effects of MB-photoactivated. The inactivation rate of cultured 8h LM BF was over 99.7% by 0.1μg/mL MB and 20min of irradiation ,exposure to 50μg/mL MB resulted in almost complete killing. When the concentration of MB was 1μg/mL at the illumination for 5min,cultured 8h BF produced 99.6% inactivation while cultured 36h BF was only 78.7%. The ability of inactivate biofilm bacteria was further enhanced at the illumination for 30min, 99.96% inactivation rate of cultured 8h BF and 99.94% of cultured 36h BF, respectively. The efficacy of MB-APDT to LM BF mainly depends on the concentration of MB and illumination time ,and LM BF were effectively inactivated.

关 键 词：激光共聚焦扫描显微镜 单增李斯特菌 生物菌膜 亚甲基蓝 光动力灭菌技术 

分 类 号：TS207.3[轻工技术与工程—食品科学]