Brazil Confirms TWO More Cases of Mad Cow Disease BSE States of Mato Grosso and Minas Gerais

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OIE Reports on Brazil BSE cases



Conclusions on transmissibility of atypical BSE among cattle

Given that cattle have been successfully infected by the oral route, at least for L-BSE, it is reasonable to conclude that atypical BSE is potentially capable of being recycled in a cattle population if cattle are exposed to contaminated feed. In addition, based on reports of atypical BSE from several countries that have not had C-BSE, it appears likely that atypical BSE would arise as a spontaneous disease in any country, albeit at a very low incidence in old cattle. In the presence of livestock industry practices that would allow it to be recycled in the cattle feed chain, it is likely that some level of exposure and transmission may occur. As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.

https://www.oie.int/fileadmin/SST/a...alopathy/AN/A_AhG_BSEsurv_RiskAss_Mar2019.pdf

MONDAY, NOVEMBER 30, 2020

REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION

https://animalhealthreportpriontse.blogspot.com/2020/11/report-of-meeting-of-oie-scientific.html

the myth that all sporadic/spontaneous BSE TSE Prion disease are not caused by the ingestion of TSE Prion contanimated feed, is just that, a myth, one never proven, and in fact, is not scientific, when;

***> Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.

***> As a result, since atypical BSE can be reasonably considered to pose a potential background level of risk for any country with cattle, the recycling of both classical and atypical strains in the cattle and broader ruminant populations should be avoided.

***> This study demonstrates that the H-type BSE agent is transmissible by the oronasal route.

***> These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.

Emerg Infect Dis. 2017 Feb; 23(2): 284–287. doi: 10.3201/eid2302.161416 PMCID: PMC5324790 PMID: 28098532

Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle

snip...

The neuroanatomical PrPSc distribution pattern of orally challenged cattle differed somewhat from that described in cattle naturally and intracerebrally challenged with L-BSE (2–6,11,13,14), The conspicuous differences between the case we report and cases of natural and experimental infection are 1) higher amounts of PrPSc in the caudal medulla oblongata and the spinal cord coupled with that in the thalamus and the more rostral brainstem and 2) relatively low amounts of PrPSc in the cerebral cortices and the olfactory bulb. Furthermore, fewer PrPSc deposits in the dorsal motor nucleus of the vagus nerve may indicate that the parasympathetic retrogressive neuroinvasion pathway does not contribute to transport of the L-BSE prion from the gut to the brain, which is in contrast to the vagus-associated transport of the agent in C-BSE (15). PrPSc accumulation in the extracerebral tissues may be a result of centrifugal trafficking of the L-BSE prion from the central nervous system along somatic or autonomic nerve fibers rather than centripetal propagation of the agent (4,6,9). Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324790/

Our study clearly confirms, experimentally, the potential risk for interspecies oral transmission of the agent of L-BSE. In our model, this risk appears higher than that for the agent of classical BSE, which could only be transmitted to mouse lemurs after a first passage in macaques (14). We report oral transmission of the L-BSE agent in young and adult primates. Transmission by the IC route has also been reported in young macaques (6,7). A previous study of L-BSE in transgenic mice expressing human PrP suggested an absence of any transmission barrier between cattle and humans for this particular strain of the agent of BSE, in contrast to findings for the agent of classical BSE (9). Thus, it is imperative to maintain measures that prevent the entry of tissues from cattle possibly infected with the agent of L-BSE into the food chain.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310119/

Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research

Title: The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge

Author item Greenlee, Justin item MOORE, S - Orise Fellow item WEST-GREENLEE, M - Iowa State University

Submitted to: Prion

Publication Type: Abstract Only

Publication Acceptance Date: 5/14/2018

Publication Date: 5/22/2018

Citation: Greenlee, J.J., Moore, S.J., West Greenlee, M.H. 2018. The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge. Prion 2018, May 22-25, 2018, Santiago de Compostela, Spain. Paper No. P98, page 116. Interpretive Summary:

Technical Abstract: In 2006, a case of H-type bovine spongiform encephalopathy (BSE) was reported in a cow with a previously unreported prion protein polymorphism (E211K). The E211K polymorphism is heritable and homologous to the E200K mutation in humans that is the most frequent PRNP mutation associated with familial Creutzfeldt-Jakob disease. Although the prevalence of the E211K polymorphism is low, cattle carrying the K211 allele develop H-type BSE with a rapid onset after experimental inoculation by the intracranial route.

The purpose of this study was to investigate whether the agents of H-type BSE or H-type BSE associated with the E211K polymorphism transmit to wild type cattle or cattle with the K211 allele after oronasal exposure.

Wild type (EE211) or heterozygous (EK211) cattle were oronasally inoculated with either H-type BSE from the 2004 US H-type BSE case (n=3) or from the 2006 US H-type case associated with the E211K polymorphism (n=4) using 10% w/v brain homogenates.

Cattle were observed daily throughout the course of the experiment for the development of clinical signs.

At approximately 50 months post-inoculation, one steer (EK211 inoculated with E211K associated H-BSE) developed clinical signs including inattentiveness, loss of body condition, weakness, ataxia, and muscle fasciculations and was euthanized.

Enzyme immunoassay confirmed that abundant misfolded protein was present in the brainstem, and immunohistochemistry demonstrated PrPSc throughout the brain.

Western blot analysis of brain tissue from the clinically affected steer was consistent with the E211K H-type BSE inoculum.

With the experiment currently at 55 months post-inoculation, no other cattle in this study have developed clinical signs suggestive of prion disease.

This study demonstrates that the H-type BSE agent is transmissible by the oronasal route.

These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.

https://www.ars.usda.gov/research/publications/publication/?seqNo115=353094

P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge

Greenlee JJ (1), Moore SJ (1), and West Greenlee MH (2) (1) United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Virus and Prion Research Unit, Ames, IA, United States (2) Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, United States.

snip...

With the experiment currently at 55 months post-inoculation, no other cattle in this study have developed clinical signs suggestive of prion disease. This study demonstrates that the H-type BSE agent is transmissible by the oronasal route.

These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.

PRION 2018 CONFERENCE ABSTRACT

THURSDAY, JUNE 25, 2020

First Report of the Potential Bovine Spongiform Encephalopathy (BSE)-Related Somatic Mutation E211K of the Prion Protein Gene (PRNP) in Cattle

https://bovineprp.blogspot.com/2020/06/first-report-of-potential-bovine.html

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