Prions in Milk from Ewes Incubating Natural Scrapie Prion Infectivity in Colostrum and Milk
2008

Prions in Milk from Ewes with Scrapie

Sample size: 175 publication 10 minutes Evidence: high

Author Information

Author(s): Lacroux Caroline, Simon Stéphanie, Benestad Sylvie L., Maillet Séverine, Mathey Jacinthe, Lugan Séverine, Corbière Fabien, Cassard Hervé, Costes Pierrette, Bergonier Dominique, Weisbecker Jean-Louis, Moldal Torffin, Simmons Hugh, Lantier Frederic, Feraudet-Tarisse Cécile, Morel Nathalie, Schelcher François, Grassi Jacques, Andréoletti Olivier

Primary Institution: UMR INRA ENVT 1225, Ecole Nationale Vétérinaire de Toulouse, France

Hypothesis

Can prions be detected in the milk of ewes incubating natural scrapie?

Conclusion

The study found prion infectivity in colostrum and milk from ewes with scrapie, raising concerns about the risk of TSE transmission through milk products.

Supporting Evidence

  • Prion infectivity was detected in colostrum and milk from ewes several months before clinical signs of scrapie appeared.
  • PrPSc accumulation was found in mammary glands of ewes with ectopic lymphoid follicles.
  • Milk from ewes with healthy mammary glands also contained prion infectivity.
  • Bioassays showed that milk and colostrum from scrapie-affected ewes could transmit the disease to mice.

Takeaway

This study shows that milk from sheep with a disease called scrapie can carry harmful prions, which could make both animals and humans sick.

Methodology

The study involved collecting milk and colostrum from ewes, testing for prion presence using immunohistochemistry and bioassays in transgenic mice.

Potential Biases

Potential bias due to the study being conducted in a specific flock with limited exposure to different TSE agents.

Limitations

The study was conducted in a single flock, which may limit the generalizability of the findings to other populations.

Participant Demographics

Ewes from the Langlade flock, primarily of Romanov breed, with various PRP genotypes.

Digital Object Identifier (DOI)

10.1371/journal.ppat.1000238

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