Excretion of BSE and scrapie prions in stools from murine models

Faeces from infected animals have been suggested as a potential source of contamination and transmission of prion diseases in the environment. This work describes the development of a procedure for the detection of PrPres in stools which is based on a detergent-based extraction and immunoprecipitation (IP). The procedure was evaluated by analyzing TSE-spiked sheep and mice faeces, and proved to be specific for PrPres with sensitivities of 5–10 μg of infected brain tissue. In order to analyze the shedding of prions, we studied stools from orally inoculated mice over 4-days post-inoculation and also stools from terminally sick scrapie-infected mice. PrPres was only detected in stools shortly after the oral ingestion of TSE agents. The procedure described could be a useful tool for studying the excretion of prions and for evaluating potential environmental contamination by prions.