151. Prions in milk from ewes incubating natural scrapie
- Author
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Hugh Simmons, Frédéric Lantier, J. Mathey, Stéphanie Simon, Hervé Cassard, Séverine Lugan, Jacques Grassi, François Schelcher, Sylvie L. Benestad, Olivier Andreoletti, Caroline Lacroux, Fabien Corbière, Jean-Louis Weisbecker, Nathalie Morel, Torffin Moldal, Dominique Bergonier, Cécile Feraudet-Tarisse, Pierrette Costes, Séverine Maillet, Interactions hôtes-agents pathogènes [Toulouse] (IHAP), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Service de Pharmacologie et Immunoanalyse (SPI), Médicaments et Technologies pour la Santé (MTS), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), National Veterinary Institute, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Physiopathologie et Toxicologie Expérimentales (UPTE), Domaine expérimental de Langlade (LANGLADE), Institut National de la Recherche Agronomique (INRA), University of Surrey (UNIS), Infectiologie Animale et Santé Publique (UR IASP), GIS infections à prion (French Research Ministry), EU FAIR (QLK-CT 2001-390), and DEFRA (SE2004, contract: CSA 6914), Institut National de la Recherche Agronomique - INRA (FRANCE), Ecole Nationale Vétérinaire de Toulouse - ENVT (FRANCE), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Technical University of Denmark [Lyngby] (DTU), Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration
- Subjects
PrPSc Proteins ,[SDV]Life Sciences [q-bio] ,animal diseases ,Scrapie ,brebis laitière ,0403 veterinary science ,Mice ,fluids and secretions ,Pregnancy ,Tissue Distribution ,lcsh:QH301-705.5 ,ComputingMilieux_MISCELLANEOUS ,2. Zero hunger ,Infectivity ,0303 health sciences ,Transmissible spongiform encephalopathy ,food and beverages ,brebis ,04 agricultural and veterinary sciences ,[SDV] Life Sciences [q-bio] ,Milk ,colostrum ,Prion ,Female ,Research Article ,lcsh:Immunologic diseases. Allergy ,040301 veterinary sciences ,Immunology ,Mice, Transgenic ,Breast milk ,Biology ,Microbiology ,prion ,03 medical and health sciences ,Mammary Glands, Animal ,Infectious Diseases/Prion Diseases ,Virology ,Nutrition/Food Security ,Genetics ,medicine ,Infectiosity ,Animals ,Humans ,Molecular Biology ,Sheep, Domestic ,030304 developmental biology ,Brain Chemistry ,Maedi ,Sheep ,medicine.disease ,lait ,nervous system diseases ,Médecine vétérinaire et santé animal ,lcsh:Biology (General) ,Colostrum ,glande mammaire ,Parasitology ,Flock ,lcsh:RC581-607 - Abstract
Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE)-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrPSc accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 µg of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species., Author Summary A decade ago, a new variant form of Creutzfeldt-Jakob disease was identified. The emergence of this prion disease in humans was the consequence of the zoonotic transmission of bovine spongiform encephalopathy through dietary exposure. Since then, the control of human exposure to prions has become a priority, and a policy based on the exclusion of known infectious materials from the food chain has been implemented. Because all investigations carried out failed to reveal evidence of infectivity in milk from affected ruminants, this product has continuously been considered as safe. In this study, we demonstrate the presence of prions in colostrum and milk from sheep incubating natural scrapie and displaying apparently healthy mammary glands. This finding indicates that milk from small ruminants could contribute to the transmission of prion disease between animals. It also raises some concern with regard to the risk to humans associated with milk products from ovine and other dairy species.
- Published
- 2008