De Roda Husman Ana Maria, Bijkerk Paul, Lodder Willemijn, Van Den Berg Harold, Pribil Walter, Cabaj Alexander, Gehringer Peter, Sommer Regina, Duizer Erwin
Microbiological Laboratory for Health Protection, National Institute for Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
Appl Environ Microbiol. 2004 Sep;70(9):5089-93. doi: 10.1128/AEM.70.9.5089-5093.2004.
Noroviruses (previously Norwalk-like viruses) are the most common viral agents associated with food- and waterborne outbreaks of gastroenteritis. In the absence of culture methods for noroviruses, animal caliciviruses were used as model viruses to study inactivation by nonionizing (253.7-nm-wavelength [UV]) and ionizing (gamma) radiation. Here, we studied the respiratory feline calicivirus (FeCV) and the presumed enteric canine calicivirus (CaCV) and compared them with the well-studied bacteriophage MS2. When UV irradiation was used, a 3-log(10) reduction was observed at a fluence of 120 J/m(2) in the FeCV suspension and at a fluence of 200 J/m(2) for CaCV; for the more resistant phage MS2 there was a 3-log(10) reduction at a fluence of 650 J/m(2). Few or no differences were observed between levels of UV inactivation in high- and low-protein-content virus stocks. In contrast, ionizing radiation could readily inactivate MS2 in water, and there was a 3-log(10) reduction at a dose of 100 Gy, although this did not occur when the phage was diluted in high-protein-content stocks of CaCV or FeCV. The low-protein-content stocks showed 3-log(10) reductions at a dose of 500 Gy for FeCV and at a dose of 300 for CaCV. The inactivation rates for both caliciviruses with ionizing and nonionizing radiation were comparable but different from the inactivation rates for MS2. Although most FeCV and CaCV characteristics, such as overall particle and genome size and structure, are similar, the capsid sequences differ significantly, making it difficult to predict human norovirus inactivation. Adequate management of UV and gamma radiation processes for virus inactivation should limit public health risks.
诺如病毒（以前称为诺沃克样病毒）是与食源性和水源性肠胃炎暴发相关的最常见病毒病原体。由于缺乏诺如病毒的培养方法，动物杯状病毒被用作模型病毒来研究非电离（253.7纳米波长[紫外线]）和电离（γ）辐射的灭活作用。在此，我们研究了呼吸道猫杯状病毒（FeCV）和推测的肠道犬杯状病毒（CaCV），并将它们与经过充分研究的噬菌体MS2进行了比较。使用紫外线照射时，在FeCV悬液中通量为120 J/m²时观察到3个对数（10）的减少，在CaCV通量为200 J/m²时观察到3个对数（10）的减少；对于更具抗性的噬菌体MS2，在通量为650 J/m²时减少3个对数（10）。在高蛋白含量和低蛋白含量的病毒原液中，紫外线灭活水平之间几乎没有差异或没有差异。相比之下，电离辐射可以很容易地使水中的MS2失活，在剂量为100 Gy时减少3个对数（10），尽管当噬菌体在高蛋白含量的CaCV或FeCV原液中稀释时不会发生这种情况。低蛋白含量的原液在FeCV剂量为500 Gy时和CaCV剂量为300时显示3个对数（10）的减少。两种杯状病毒在电离和非电离辐射下的灭活率相当，但与MS2的灭活率不同。尽管大多数FeCV和CaCV的特征，如总体颗粒和基因组大小及结构相似，但衣壳序列差异很大，这使得预测人类诺如病毒的灭活变得困难。对紫外线和γ辐射过程进行适当管理以实现病毒灭活应能降低公共卫生风险。
