Friday, November 18, 2016
IMPORTANT: SAWCorp CWD Test is Not APHIS Approved
USDA Animal and Plant Health Inspection Service sent this bulletin at 11/18/2016 11:43 AM EST
SAWCorp, a private company, recently issued a press release launching a new, patented live-animal blood test for the detection of chronic wasting disease (CWD) in cervids. A subsequent press release from the same company stated that the USDA is reviewing the test for use in the CWD program.
USDA’s Animal and Plant Health Inspection Service (APHIS) does not recognize protein misfolding cyclic amplification (PMCA) prion blood tests as an official test for CWD, bovine spongiform encephalopathy,or scrapie. By definition, an official CWD test is, “Any test for the diagnosis of CWD approved by the Administrator and conducted in a laboratory approved by the Administrator in accordance with §55.8 of this part” (9 CFR Part 55). The criteria necessary for approval as an official CWD test includes a standardized test protocol, data to support reproducibility, data to support suitability, and data to support the sensitivity and specificity of the test. While APHIS supports emerging technologies, no company has submitted the data needed for APHIS to evaluate the PMCA prion blood test. In addition, APHIS is aware of no peer-reviewed scientific publications that establish the efficacy of PMCA as a detection method for CWD in cervid blood.
If producers elect to use a PMCA test, APHIS will consider positive results to be “suspect” cases that must be confirmed using an official CWD test. APHIS will not recognize negative or “not detected” PMCA test results for herd certification or interstate movement purposes.
***
Animal TSE workshop:
Updated Diagnosis and Epidemiology of Animal Prion Diseases for Food Safety and Security.
Prion diseases in field and farm animals pose a risk to animals, their environment and our food. The mechanisms of agent development and its spread in the host and environment are challenging subjects for scientists and policy makers. While some prion diseases seems to be disappearing thanks to adequate knowledge on diagnosis, detection and breeding, there is also more awareness of the potential emergence of new prion disease forms as with the susceptibility of goats, atypical variant in ruminant, chronic wasting disease (CWD) in cervid species, PrP related disorders in humans, and potentially the susceptibility of certain rodent species. Updated diagnosis system is critical for the risk assessment and risk managements in the Food Chain of the meat products. Appropriate presentations have been actively sought by the organizers including invited speakers and from interesting abstract sent to the Prion2016 conference. We hope this collection of presentations in a smaller forum than the main conference will stimulate the scientific interest. These discussions will contribute to technical advances to sustain the global food and agriculture systems from input to final consumption, taking into account changing consumer and social interests.
This meeting is a follow-up of previous workshop organized by EU-supported NeuroPrion task groups. Since past workshops were in Europe, Canada and USA. This is the first global workshop in Asian-Pacific Regional area.
In this symposium, bovine spongiform encephalopathy (BSE) is reviewed for adoption of One Health approaches. A novel sensitive assay for prions Real-Time-Quaking-Induced-Conversion (RT-QuIC) assays will be discussed not only in human but also in many kinds of animals. RT-QuIC assays can rapidly detect sub-infectious doses of prion seeding activity and will be used successfully to detect multiple human, bovine, cervid, ovine, hamster and mouse prion strains in a variety of biological tissues such as cerebrospinal fluid, saliva, blood and nasal fluids. Besides conventional Protein Misfolding Cyclic Amplification (PMCA) method will be compared with RT-QuIC in many kinds of animals. The development of technology (novel diagnosis and decontamination) to produce safe foods or food materials that further promote human health is greatly anticipated.
This workshop is sponsored by the OECD Co-operative Research Programme.
Organizers Takashi Yokoyama, National Institute of Animal Health, NARO Hyuu-Joo Sohn Animal and Plant Quarantine Agency (QIA), Ministry for Food, Agriculture, Forestry, and Fisheries, Republic of Korea Takashi Onodera Research Centre for Food Safety, The University of Tokyo
***at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified.
P-145 Estimating chronic wasting disease resistance in cervids using real time quaking- induced conversion
Nicholas J Haley1, Rachel Rielinqer2, Kristen A Davenport3, W. David Walter4, Katherine I O'Rourke5, Gordon Mitchell6, Juergen A Richt2
1 Department of Microbiology and Immunology, Midwestern University, United States; 2Department of Diagnostic Medicine and Pathobiology, Kansas State University; 3Prion Research Center; Colorado State University; 4U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit; 5Agricultural Research Service, United States Department of Agriculture; 6Canadian Food Inspection Agency, National and OlE Reference Laboratory for Scrapie and CWO
In mammalian species, the susceptibility to prion diseases is affected, in part, by the sequence of the host's prion protein (PrP). In sheep, a gradation from scrapie susceptible to resistant has been established both in vivo and in vitro based on the amino acids present at PrP positions 136, 154, and 171, which has led to global breeding programs to reduce the prevalence of scrapie in domestic sheep. In cervids, resistance is commonly characterized as a delayed progression of chronic wasting disease (CWD); at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified. To model the susceptibility of various naturally-occurring and hypothetical cervid PrP alleles in vitro, we compared the amplification rates and efficiency of various CWD isolates in recombinant PrPC using real time quaking-induced conversion. We hypothesized that amplification metrics of these isolates in cervid PrP substrates would correlate to in vivo susceptibility - allowing susceptibility prediction for alleles found at 10 frequency in nature, and that there would be an additive effect of multiple resistant codons in hypothetical alleles. Our studies demonstrate that in vitro amplification metrics predict in vivo susceptibility, and that alleles with multiple codons, each influencing resistance independently, do not necessarily contribute additively to resistance. Importantly, we found that the white-tailed deer 226K substrate exhibited the slowest amplification rate among those evaluated, suggesting that further investigation of this allele and its resistance in vivo are warranted to determine if absolute resistance to CWD is possible.
***at present, no cervid PrP allele conferring absolute resistance to prion infection has been identified.
PRION 2016 CONFERENCE TOKYO
P.105: RT-QuIC models trans-species prion transmission
Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA
Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD.
***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.
================
***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***
================
Saturday, February 20, 2016
Seeded amplification of chronic wasting disease prions in nasal brushings and recto-anal mucosa associated lymphoid tissues from elk by real time quaking-induced conversion
Seeded amplification of chronic wasting disease prions in nasal brushings and recto-anal mucosa associated lymphoid tissues from elk by real time quaking-induced conversion
Nicholas J. Haley#,a, Chris Siepkera, Laura L. Hoon-Hanksb, Gordon Mitchellc, W. David Walterd, Matteo Mancae, Ryan J. Monellof, Jenny G. Powersf, Margaret A. Wildf, Edward A. Hooverb, Byron Caugheye and Jürgen A. Richta + Author Affiliations Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University (KSU), Manhattan, KS, USAa Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USAb Canadian Food Inspection Agency, National and OIE Reference Laboratory for Scrapie and CWD, Ottawa Laboratory Fallowfield, Ottawa, ON, Canadac U.S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, The Pennsylvania State University, University Park, PA, USAd TSE/Prion Biochemistry Section, Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories (RML), National Institute of Allergy and Infectious Diseases, Hamilton, MT, USAe National Park Service, Biological Resources Division, 1201 Oak Ridge Drive, Suite 200, Fort Collins, Colorado 80525, USAf
ABSTRACT
Chronic wasting disease (CWD), a transmissible spongiform encephalopathy of cervids, was first documented nearly fifty years ago in Colorado and Wyoming, and has since been detected across North America and to the Republic of Korea. The expansion of this disease makes the development of sensitive diagnostic assays and antemortem sampling techniques crucial for the mitigation of spread; this is especially true in cases of relocation/reintroduction, or prevalence studies in large or protected herds where depopulation may be contraindicated. This study sought to evaluate the sensitivity of the real-time quaking-induced conversion (RT-QuIC) assay in recto-anal mucosa associated lymphoid tissue (RAMALT) biopsies and nasal brushings collected antemortem. These findings were compared to results from ante- and postmortem samples evaluated using immunohistochemistry (IHC). RAMALT samples were collected from populations of farmed and free-ranging Rocky Mountain elk (Cervus elaphus nelsoni, n=323), with nasal brushes collected from a subpopulation of these animals (n=205). We hypothesized the sensitivity of RT-QuIC would be comparable to IHC in RAMALT, and would correspond to IHC of postmortem tissues. We found RAMALT sensitivity (77.3%) to be highly correlative between RT-QuIC and IHC. Sensitivity was lower when testing nasal brushings (34%), though both RAMALT and nasal brush sensitivities were dependent on both PRNP genotype and disease progression determined by obex score. These data suggest that RT-QuIC, like IHC, is a relatively sensitive assay for detection of CWD prions in RAMALT biopsies, and with further investigation has potential for large scale and rapid automated testing for CWD in antemortem samples. FOOTNOTES ↵#Corresponding author (e-mail: nicholas.j.haley@gmail.com) Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Sunday, February 14, 2016
Antemortem detection of chronic wasting disease prions in nasal brush collections and rectal biopsies from white-tailed deer by real time quaking-induced conversion
Friday, August 28, 2015
*** Chronic Wasting Disease CWD TSE Prion Diagnostics and subclinical infection
Monday, July 18, 2016
Texas Parks Wildlife Dept TPWD HIDING TSE (CWD) in Deer Herds, Farmers Sampling Own Herds, Rapid Testing, False Negatives, a Recipe for Disaster
Sunday, November 13, 2016
Horizontal Transmission of Chronic Wasting Disease in Reindeer CDC Volume 22, Number 12—December 2016
TSS
4 Comments:
This comment has been removed by a blog administrator.
This comment has been removed by a blog administrator.
This comment has been removed by a blog administrator.
This comment has been removed by a blog administrator.
Post a Comment
Subscribe to Post Comments [Atom]
<< Home