Photoreactivation of Legionella pneumophila after inactivation by low- or medium-pressure ultraviolet lamp.
Photoreactivation of Legionella pneumophila after inactivation by low- or medium-pressure ultraviolet lamp.
复制标题
DOI：
10.1016/j.watres.2004.03.024
复制
发表时间：
2004-06
期刊：
影响因子：
12.8
通讯作者：
K. Oguma;H. Katayama;S. Ohgaki
中科院分区：
文献类型：
--
作者：
K. Oguma;H. Katayama;S. Ohgaki
研究了低压 (LP) 或中压 (MP) 紫外线灯灭活后嗜肺军团菌的光再活化情况，并与大肠杆菌进行了比较。采用核酸内切酶敏感位点（ESS）测定法测定嗜肺军团菌或大肠杆菌基因组DNA中紫外线诱导的嘧啶二聚体的数量，同时还通过培养方法研究每种细菌的存活率。嗜肺军团菌进行光再激活，嘧啶二聚体几乎完全修复，与存活率的快速恢复相关。当光复活完成时，LP 或 MP 紫外灯对嗜肺军团菌进行 3log 灭活分别导致 0.5log 或 0.4log 灭活。有趣的是，嗜肺军团菌在 LP 和 MP 紫外灯照射后表现出相同的光再激活，而大肠杆菌的光再激活在 MP 紫外灯灭活后受到显着抑制。这项研究表明，需要注意设计和操作针对嗜肺军团菌的紫外线消毒系统。进一步暗示，当光复活发生时，大肠杆菌不能正确指示紫外线消毒系统中嗜肺军团菌的命运。
Photoreactivation of Legionella pneumophila after the inactivation by low-pressure (LP) or medium-pressure (MP) UV lamp was investigated in comparison with that of Escherichia coli. An endonuclease sensitive site (ESS) assay was used to determine the number of UV-induced pyrimidine dimers in the genome DNA of L. pneumophila or E. coli, while the survival ratio of each bacterium was also investigated by cultivation methods. L. pneumophila performed photoreactivation with almost complete repair of pyrimidine dimers associated with the quick recovery of survival ratio. A 3log inactivation of L. pneumophila by LP or MP UV lamp was, respectively, resulted in 0.5log or 0.4log inactivation when photoreactivation was completed. Interestingly, L. pneumophila performed equivalent photoreactivation after LP and MP UV lamp exposures while photoreactivation of E. coli was significantly repressed after the inactivation by MP UV lamp. This study indicated that an attention would be required to design and operate a UV disinfection system targeting L. pneumophila. It was further implied that E. coli would not correctly indicate the fate of L. pneumophila in UV disinfection systems when photoreactivation takes place.