Experimental transmission of bovine spongiform encephalopathy to European red deer Cervus elaphus elaphusReportar como inadecuado




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BMC Veterinary Research

, 4:17

First Online: 28 May 2008Received: 17 December 2007Accepted: 28 May 2008

Abstract

BackgroundBovine spongiform encephalopathy BSE, a member of the transmissible spongiform encephalopathies TSE, primarily affects cattle. Transmission is via concentrate feed rations contaminated with infected meat and bone meal MBM. In addition to cattle, other food animal species are susceptible to BSE and also pose a potential threat to human health as consumption of infected meat products is the cause of variant Creutzfeldt-Jakob disease in humans, which is invariably fatal. In the UK, farmed and free ranging deer were almost certainly exposed to BSE infected MBM in proprietary feeds prior to legislation banning its inclusion. Therefore, although BSE has never been diagnosed in any deer species, a possible risk to human health remains via ingestion of cervine products. Chronic wasting disease CWD, also a TSE, naturally infects several cervid species in North America and is spreading rapidly in both captive and free-ranging populations.

ResultsHere we show that European red deer Cervus elaphus elaphus are susceptible to intra-cerebral i-c challenge with BSE positive cattle brain pool material resulting in clinical neurological disease and weight loss by 794–1290 days and the clinical signs are indistinguishable to those reported in deer with CWD. Spongiform changes typical of TSE infections were present in brain and accumulation of the disease-associated abnormal prion protein PrP was present in the central and peripheral nervous systems, but not in lymphoid or other tissues. Western immunoblot analysis of brain material showed a similar glycosylation pattern to that of BSE derived from infected cattle and experimentally infected sheep with respect to protease-resistant PrP isoforms. However, the di-, mono- and unglycosylated bands migrated significantly p < 0.001 further in the samples from the clinically affected deer when compared to BSE infected brains of cattle and sheep.

ConclusionThis study shows that deer are susceptible to BSE by intra-cerebral inoculation and display clinical signs and vacuolar pathology that are similar to those of CWD. These findings highlight the importance of preventing the spread to Europe of CWD from North America as this may necessitate even more extensive testing of animal tissues destined for human consumption within the EU. Although the absence of PrP in lymphoid and other non-neurological tissues potentially limits the risk of transmission to humans, the replication of TSE agents in peripheral tissues following intra-cerebral challenge is often limited. Thus the assessment of risk posed by cervine BSE as a human pathogen or for environmental contamination should await the outcome of ongoing oral challenge experiments.

Electronic supplementary materialThe online version of this article doi:10.1186-1746-6148-4-17 contains supplementary material, which is available to authorized users.

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Autor: Mark P Dagleish - Stuart Martin - Philip Steele - Jeanie Finlayson - Sílvia Sisó - Scott Hamilton - Francesca Chianini -

Fuente: https://link.springer.com/







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