Polo David, García-Fernández Irene, Fernández-Ibáñez Pilar, Romalde Jesús L
Department of Microbiology and Parasitology, CIBUS-School of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain.
Solar Platform of Almería, CIEMAT, Tabernas, Spain.
Int Microbiol. 2015 Mar;18(1):41-9. doi: 10.2436/20.1501.01.233.
This study evaluates the effectiveness of solar water disinfection (SODIS) in the reduction and inactivation of hepatitis A virus (HAV) and of the human Norovirus surrogate, murine Norovirus (MNV-1), under natural solar conditions. Experiments were performed in 330 ml polyethylene terephthalate (PET) bottles containing HAV or MNV-1 contaminated waters (10(3) PFU/ml) that were exposed to natural sunlight for 2 to 8 h. Parallel experiments under controlled temperature and/or in darkness conditions were also included. Samples were concentrated by electropositive charged filters and analysed by RT-real time PCR (RT-qPCR) and infectivity assays. Temperature reached in bottles throughout the exposure period ranged from 22 to 40ºC. After 8 h of solar exposure (cumulative UV dose of ~828 kJ/m2 and UV irradiance of ~20 kJ/l), the results showed significant (P<0.05) reductions from 4.0 (+/-0.56)x10(4) to 3.15 (+/-0.69)x10(3) RNA copies/100ml (92.1%, 1.1 log) for HAV and from 5.91 (+/-0.59)x10(4) to 9.24 (+/-3.91)x10(3) RNA copies/100 ml (84.4%, 0.81 log) for MNV-1. SODIS conditions induced a loss of infectivity between 33.4% and 83.4% after 4 to 8 h in HAV trials, and between 33.4% and 66.7% after 6 h to 8 h in MNV-1 trials. The results obtained indicated a greater importance of sunlight radiation over the temperature as the main factor for viral reduction.
本研究评估了在自然阳光条件下，太阳能水消毒法（SODIS）对甲型肝炎病毒（HAV）以及人类诺如病毒替代物——鼠诺如病毒（MNV-1）的减少和灭活效果。实验在装有受HAV或MNV-1污染的水（10³ PFU/ml）的330毫升聚对苯二甲酸乙二酯（PET）瓶中进行，这些瓶子在自然阳光下暴露2至8小时。还包括在受控温度和/或黑暗条件下的平行实验。样本通过带正电荷的过滤器浓缩，并通过逆转录实时聚合酶链反应（RT-qPCR）和感染性测定进行分析。在整个暴露期间，瓶子内达到的温度范围为22至40ºC。经过8小时的阳光照射（累积紫外线剂量约为828 kJ/m²，紫外线辐照度约为20 kJ/l），结果显示，HAV的RNA拷贝数从4.0（±0.56）×10⁴降至3.15（±0.69）×10³/100ml（92.1%，1.1个对数），差异显著（P<0.05）；MNV-1的RNA拷贝数从5.91（±0.59）×10⁴降至9.24（±3.91）×10³/100ml（84.4%，0.81个对数）。在HAV试验中，SODIS条件在4至8小时后导致33.4%至83.4%的感染性丧失；在MNV-1试验中，在6至8小时后导致33.4%至66.7%的感染性丧失。获得的结果表明，作为病毒减少的主要因素，阳光辐射比温度更为重要。
