Kuznetsova Alsu, McKenzie Debbie, Cullingham Catherine, Aiken Judd M
Agricultural, Life and Environmental Sciences Faculty, University of Alberta, Edmonton, AB T6G 2G8, Canada.
Faculty of Science, University of Alberta, Edmonton, AB T6G 2M8, Canada.
Pathogens. 2020 Apr 23;9(4):311. doi: 10.3390/pathogens9040311.
Chronic wasting disease (CWD) is a contagious prion disease of cervids. The infectious agent is shed from animals at the preclinical and clinical stages of disease where it persists in the environment as a reservoir of CWD infectivity. In this study, we demonstrate that long-term incubation of CWD prions (generated from tg-mice infected with deer or elk prions) with illite, montmorillonite (Mte) and whole soils results in decreased recovery of PrP, suggesting that binding becomes more avid and irreversible with time. This continual decline of immunoblot PrP detection did not correlate with prion infectivity levels. Bioassay showed no significant differences in incubation periods between mice inoculated with 1% CWD brain homogenate (BH) and with the CWD-BH pre-incubated with quartz or Luvisolic Ae horizon for 1 or 30 weeks. After 55 weeks incubation with Chernozem and Luvisol, bound PrP was not detectable by immunoblotting but remained infectious. This study shows that although recovery of PrP bound to soil minerals and whole soils with time become more difficult, prion infectivity is not significantly altered. Detection of prions in soil is, therefore, not only affected by soil type but also by length of time of the prion-soil interaction.
慢性消耗病（CWD）是一种鹿科动物的传染性朊病毒病。在疾病的临床前期和临床阶段，感染源会从动物体内排出，并在环境中持续存在，成为慢性消耗病感染性的储存库。在本研究中，我们证明，将慢性消耗病朊病毒（由感染鹿或麋鹿朊病毒的转基因小鼠产生）与伊利石、蒙脱石（Mte）和全土长期孵育，会导致PrP回收率降低，这表明随着时间的推移，结合变得更加紧密且不可逆。免疫印迹法检测到的PrP持续下降与朊病毒感染性水平无关。生物测定显示，接种1%慢性消耗病脑匀浆（BH）的小鼠与预先与石英或灰化淀积层土壤孵育1周或30周的慢性消耗病脑匀浆接种的小鼠之间，潜伏期没有显著差异。与黑钙土和淋溶土孵育55周后，免疫印迹法检测不到结合的PrP，但仍具有感染性。这项研究表明，虽然随着时间的推移，与土壤矿物质和全土结合的PrP越来越难回收，但朊病毒的感染性没有显著改变。因此，土壤中朊病毒的检测不仅受土壤类型的影响，还受朊病毒与土壤相互作用时间长短的影响。
