Cargando…

Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers

Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infecti...

Descripción completa

Detalles Bibliográficos
Autores principales: Foster, James D., Goldmann, Wilfred, Hunter, Nora
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3832582/
https://www.ncbi.nlm.nih.gov/pubmed/24260219
http://dx.doi.org/10.1371/journal.pone.0079433
_version_ 1782291704192172032
author Foster, James D.
Goldmann, Wilfred
Hunter, Nora
author_facet Foster, James D.
Goldmann, Wilfred
Hunter, Nora
author_sort Foster, James D.
collection PubMed
description Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep.
format Online
Article
Text
id pubmed-3832582
institution National Center for Biotechnology Information
language English
publishDate 2013
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-38325822013-11-20 Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers Foster, James D. Goldmann, Wilfred Hunter, Nora PLoS One Research Article Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep. Public Library of Science 2013-11-18 /pmc/articles/PMC3832582/ /pubmed/24260219 http://dx.doi.org/10.1371/journal.pone.0079433 Text en © 2013 Foster et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Foster, James D.
Goldmann, Wilfred
Hunter, Nora
Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title_full Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title_fullStr Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title_full_unstemmed Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title_short Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
title_sort evidence in sheep for pre-natal transmission of scrapie to lambs from infected mothers
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3832582/
https://www.ncbi.nlm.nih.gov/pubmed/24260219
http://dx.doi.org/10.1371/journal.pone.0079433
work_keys_str_mv AT fosterjamesd evidenceinsheepforprenataltransmissionofscrapietolambsfrominfectedmothers
AT goldmannwilfred evidenceinsheepforprenataltransmissionofscrapietolambsfrominfectedmothers
AT hunternora evidenceinsheepforprenataltransmissionofscrapietolambsfrominfectedmothers