RT-QuIC detection of PrPsc in fecal samples from CWD infected White-tailed Deer using Bank Vole Substrate

Authors: Hwang, Soyoun; Greenlee, Justin; Nicholson, Eric

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2021
Publication Date: 3/4/2021
Citation: Hwang, S., Greenlee, J.J., Nicholson, E.M. 2021. RT-QuIC detection of PrPsc in fecal samples from CWD infected White-tailed Deer using Bank Vole Substrate. Frontiers in Veterinary Science. 8. Article 643754. https://doi.org/10.3389/fvets.2021.643754.
DOI: https://doi.org/10.3389/fvets.2021.643754

Interpretive Summary: Chronic wasting disease (CWD) is a transmissibe spongiform encephalopathy (TSE) in free ranging and captive cervid species in North America, South Korea, Finland, Norway, and Sweden. The disease process is ultimately fatal and case numbers are increasing at least in part due to the relative ease of animal to animal transmission in natural settings. The disease process occurs through the misfolding a of normally occuring protein. Detection of this misfolded protein is the only known means by which a prion disease can be diagnosed. Typically this is only possible using tissues that are only available after death, such as brain. A recently developed approach for the detection of this misfolded protein uses a technique referred to as Real-time quaking induced conversion (RT-QuIC). RT-QuIC amplifies the amount of misfolded protein available for detection allowing for detection of smaller amounts of the prion protein that are present in other tissues, secretions, and excretions. In this work we present a method to detection prions in fecal samples of white tailed deer infected with chronic wasting disease (CWD) well before the onset of clinical disease.

Technical Abstract: Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) that is fatal to free range and captive cervids. CWD has been reported in the United States, Canada, South Korea, Norway, Finland, and Sweden, and the case numbers in both wild and farmed cervids are increasing rapidly. Studies indicate that lateral transmission of cervids likely occurs through the shedding of infectious prions in saliva, feces, urine and blood into the environment. Therefore, detection of CWD early in the incubation time is advantageous for the disease management. In this study, we adapt real-time quaking-induced conversion (RT-QuIC) assays to detect the seeding activity of CWD prions in feces samples from clinical and preclinical white-tailed deer. By optimizing reaction conditions for temperature as well as the salt and salt concentration, prion seeding activity well before the onset of clinical signs using RT-QuIC with the earliest timepoint collected (6 months post-inoculation) showing seeding consistent with prion disease under the conditions used. The combination of a highly sensitive detection tool paired with a sample type that may be collected non-invasively allows a useful tool to support CWD surveillance in wild and captive cervids.