Department of Medical Microbiology and Immunology, Creighton University, Omaha, Nebraska, 68178, United States of America.
Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, 55108, United States of America.
Environ Int. 2022 Aug;166:107347. doi: 10.1016/j.envint.2022.107347. Epub 2022 Jun 13.
Chronic wasting disease (CWD) has been identified in 30 states in the United States, four provinces in Canada, and recently emerged in Scandinavia. The association of CWD prions with environmental materials such as soil, plants, and surfaces may enhance the persistence of CWD prion infectivity in the environment exacerbating disease transmission. Identifying and quantifying CWD prions in the environment is significant for prion monitoring and disease transmission control. A systematic method for CWD prion quantification from associated environmental materials, however, does not exist. In this study, we developed an innovative method for extracting prions from swabs and recovering CWD prions swabbed from different types of surfaces including glass, stainless steel, and wood. We found that samples dried on swabs were unfavorable for prion extraction, with the greatest prion recovery from wet swabs. Using this swabbing technique, the recovery of CWD prions dried to glass or stainless steel was approximately 30% in most cases, whereas that from wood was undetectable by conventional prion immunodetection techniques. Real-time quake-induced conversion (RT-QuIC) analysis of these same samples resulted in an increase of the detection limit of CWD prions from stainless steel by 4 orders of magnitude. More importantly, the RT-QuIC detection of CWD prions recovered from stainless steel surfaces using this method was similar to the original CWD prion load applied to the surface. This combined surface swabbing and RT-QuIC detection method provides an ultrasensitive means for prion detection across many settings and applications.
慢性消耗病（CWD）已在美国 30 个州、加拿大 4 个省被发现，最近又出现在斯堪的纳维亚。CWD 朊病毒与土壤、植物和表面等环境物质的关联可能会增强 CWD 朊病毒在环境中的感染性持久性，从而加剧疾病的传播。鉴定和量化环境中的 CWD 朊病毒对于朊病毒监测和疾病传播控制具有重要意义。然而，目前还没有从相关环境材料中定量 CWD 朊病毒的系统方法。在这项研究中，我们开发了一种从拭子中提取朊病毒并回收从不同类型表面（包括玻璃、不锈钢和木材）拭取的 CWD 朊病毒的创新方法。我们发现，拭子上干燥的样本不利于朊病毒提取，而湿润拭子上的朊病毒回收率最高。使用这种拭子技术，在大多数情况下，玻璃或不锈钢上干燥的 CWD 朊病毒回收率约为 30%，而木材上的 CWD 朊病毒回收率则无法用传统的朊病毒免疫检测技术检测到。对这些相同样本进行实时震颤诱导转化（RT-QuIC）分析后，发现 CWD 朊病毒在不锈钢上的检测限提高了 4 个数量级。更重要的是，使用这种方法从不锈钢表面回收的 CWD 朊病毒的 RT-QuIC 检测结果与最初施加到表面的 CWD 朊病毒负荷相似。这种结合表面拭子和 RT-QuIC 检测的方法为在许多环境和应用中进行朊病毒检测提供了一种超灵敏的手段。
