Characterization of Classical Sheep Scrapie in White-tailed Deer after Experimental Oronasal Exposure

All deer inoculated oronasally with classic sheep scrapie accumulated PrPSc with a tissue distribution similar to deer with chronic wasting disease (CWD). Molecular profiles of PrPSc from deer with scrapie were difficult to differentiate from deer with CWD. Background Classic scrapie is a prion disease of sheep and goats that is associated with accumulation of abnormal prion protein (PrPSc) in the central nervous and lymphoid tissues. Chronic wasting disease (CWD) is the prion disease of cervids. This study was conducted to determine the susceptibility of white-tailed deer (WTD) to the classic scrapie agent. Methods We inoculated WTD (n = 5) by means of a concurrent oral/intranasal exposure with the classic scrapie agent from sheep or oronasally with the classic scrapie agent from goats (n = 6). Results All deer exposed to the agent of classic scrapie from sheep accumulated PrPSc. PrPSc was detected in lymphoid tissues at preclinical time points, and necropsies in deer 28 months after inoculation showed clinical signs, spongiform lesions, and widespread PrPSc in neural and lymphoid tissues. Western blots on samples from the brainstem, cerebellum, and lymph nodes of scrapie-infected WTD have a molecular profile similar to CWD and distinct from samples from the cerebral cortex, retina, or the original classic scrapie inoculum. There was no evidence of PrPSc in any of the WTD inoculated with classic scrapie prions from goats. Conclusions WTD are susceptible to the agent of classic scrapie from sheep, and differentiation from CWD may be difficult.

Automated summary

The study found that white-tailed deer are susceptible to the classic scrapie agent from sheep, and the molecular profiles of PrPSc in infected deer are difficult to differentiate from those with chronic wasting disease (CWD).