Shin Gwy-Am, Linden Karl G
a Department of Environmental Engineering, Ajou University, 206 World cup-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, South Korea, 443-749.
b Civil, Environmental, and Architectural Engineering, University of Colorado at Boulder, 428 UCB, Boulder, CO 80309, USA.
Can J Microbiol. 2015 Jul;61(7):513-6. doi: 10.1139/cjm-2014-0844. Epub 2015 Apr 20.
In this study, we determined the repair capabilities of Giardia lamblia cysts when they were exposed to low-pressure (LP) UV and then 4 different repair conditions. A UV collimated beam apparatus was used to expose shallow suspensions of G. lamblia cysts in buffered reagent water (PBS, pH 7.2) to various doses of LP UV irradiation. After UV irradiation, samples were exposed to 4 repair conditions (light and dark repair conditions with 2 temperatures (25 °C and 37 °C) for each condition). The inactivation of G. lamblia cysts by LP UV was very extensive (∼ 5 log10) even with a low dose of LP UV (1 mJ/cm(2)). More importantly, there was significant restoration of infectivity in G. lamblia cysts when they were exposed to a low dose of LP UV and then to all the repair conditions tested. Overall, the results of this study indicate that G. lamblia cysts do have the ability to repair their UV-damaged DNA when they are exposed to low doses of LP UV irradiation. This is the first study to report the presence of repair in UV-irradiated G. lamblia cysts.
在本研究中，我们测定了蓝氏贾第鞭毛虫包囊在暴露于低压（LP）紫外线后再置于4种不同修复条件下时的修复能力。使用紫外线平行光束装置将缓冲试剂水（pH 7.2的磷酸盐缓冲盐水）中的蓝氏贾第鞭毛虫包囊浅悬浮液暴露于不同剂量的LP紫外线照射下。紫外线照射后，将样品置于4种修复条件下（每种条件有25°C和37°C两种温度的光照和黑暗修复条件）。即使使用低剂量的LP紫外线（1 mJ/cm²），LP紫外线对蓝氏贾第鞭毛虫包囊的灭活作用也非常广泛（约5个对数级）。更重要的是，当蓝氏贾第鞭毛虫包囊暴露于低剂量的LP紫外线后再置于所有测试的修复条件下时，其感染性有显著恢复。总体而言，本研究结果表明，蓝氏贾第鞭毛虫包囊在暴露于低剂量的LP紫外线照射时确实有能力修复其受紫外线损伤的DNA。这是第一项报道紫外线照射后的蓝氏贾第鞭毛虫包囊存在修复现象的研究。
