Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
77. Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
Kaitlyn M. Wagnera, Caitlin Ott-Connb, Kelly Strakab, Bob Dittmarc, Jasmine Battend, Robyn Piercea, Mercedes Hennessya, Elizabeth Gordona, Brett Israela, Jenn Ballarde and Mark D Zabela
aPrion Research Center at Colorado State University; bMichigan Department of Natural Resources; cTexas Parks and Wildlife Department; dMissouri Department of Conservation, 5. Arkansas Game and Fish Commission
CONTACT Kaitlyn M. Wagner miedkait@rams.colostate.edu
ABSTRACT
Background/Introduction: Chronic wasting disease (CWD) is an invariably fatal prion disease affecting captive and free-ranging cervids, including white-tailed deer, mule deer, moose, elk, and reindeer. Since the initial description of the disease in the 1960’s, CWD has spread to 23 states, 3 Canadian Provinces, South Korea, Norway and, most recently, Finland. While some outbreaks of CWD were caused by transport of infected animals from endemic regions, the origin of CWD in other epizootics is unclear and has not been characterized. Previous studies have shown that there are two distinct strains of CWD. However, the continuous spread and the unclear origin of several outbreaks warrant continued surveillance and further characterization of strain diversity.
Materials and Methods: To address these knowledge gaps, we used biochemical tests to assess strain differences between CWD outbreaks in Michigan, Texas, Missouri, and Colorado, USA. Brain or lymph node samples were homogenized and digested in 50 µg/mL proteinase K (PK). These samples were then run on a Western blot to assess glycoform ratio and electrophoretic mobility. Texas samples were digested in 100 µg/mL PK. To assess conformational stability, brain or lymph node homogenates were incubated in increasing concentrations of guanidine hydrochloride from 0 M to 4 M in 0.5 M increments. Samples were then precipitated in methanol overnight, washed and PK digested in 50 µg/mL PK before slot blotting.
Results: Our results have found significant differences in glycoform ratio between CWD from Michigan and Colorado, but no differences were observed in conformational stability assays. Interestingly, when testing our CWD isolates from Texas to analyse electrophoretic mobility and glycoform ratio, we found that these samples did not exhibit the characteristic band shift when treated with PK, but PK resistant material remained. Additionally, results from our conformational stability assay demonstrate a unique profile of these Texas isolates. Testing of samples from Missouri is currently underway.
Conclusions: Thus far, our data indicate that there are strain differences between CWD circulating in Michigan and CWD in Colorado and provide important insight into CWD strain differences between two non-contiguous outbreaks. We have also identified a unique strain of CWD in Texas with biochemical strain properties not seen in any of our other CWD isolates. These results highlight the importance of continued surveillance to better understand this devastating disease. These results have important implications for CWD emergence, evolution and our understanding of prion strain heterogeneity on the landscape.
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115. Diversity of chronic wasting disease prion strains
Camilo Duque Velásqueza, Elizabeth Triscotta, Chiye Kima, Jacques Van der Merwea, Samia Hannaouib, Trent Bollingerc, Christina Carlsond, Sylvie Benestade, Sabine Gilchb, Judd Aikenf and Debbie McKenziea
aDepartment of Biological Sciences, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada; bDepartment of Ecosystem and Public Health, Calgary Prion Research Unit, University of Calgary, Calgary, Canada; cDepartment of Veterinary Pathology, Canadian Wildlife Health Cooperative, University of Saskatchewan, Saskatoon, Canada; dU.S. Geological Survey-National Wildlife Health Center, Madison, WI, USA; eNorwegian Veterinary Institute, Oslo and Trondheim, Norway; fDepartment of Agricultural, Food and Nutritional Sciences, Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada
ABSTRACT
Chronic Wasting Disease (CWD) prions affect a variety of cervid species. The expansion of the CWD geographic range and the increasing prevalence makes CWD a concern for wildlife, livestock, and human health. Prion pathogenesis results from the template-directed misfolding of cellular prion proteins (PrPC) into conformational species (e.g. PrPCWD) associated with distinct strains. We propose that cervid cellular prion protein (PrPC) polymorphisms have resulted in prion conformational diversification and speciation (i.e. by adaptive radiation) resulting in emergence of novel CWD strains. New prion strain conformers emerge following transmission between cervids expressing different PrPC amino acid polymorphisms [1-4]. Emergent CWD strains can have novel transmission properties that enable them to infect host species previously considered resistant, suggesting an increase in zoonotic risk as strain-conformers diversify and evolve [2, 3]. We are comparing field CWD isolates of different cervid species from various regions of North America and Norway and have identified differences in biochemical properties of PrPCWD, in vitro and ex vivo propagation and transmission into transgenic mice expressing deer and elk PrP (tgDeer – 96G, tgDeer – 96S, and tgElk-E226) as well as C57Bl6 mice and hamsters. Variations in PrP-res type and protease sensitivity were observed following treatment with proteinase K. Comparison of the PMCA seeding activity using deer and elk PrPC as substrates revealed differences between elk CWD isolates. ElK21 cells also responded differently to various cervid prions. Transmission was efficient for all isolates in tg33 and tgElk mice; however, only a few isolates were able to propagate in host expressing S96 deer PrPC, which has been shown to impose a strong transmission barrier, providing a means of differential selection of CWD strains [2]. Transmission differences were observed following interspecies transmission. While some white-tailed deer and mule deer isolates failed to transmit into hamsters, other isolates transmitted with a low attack rate but considerable sub-clinical infection. These isolates had a migration pattern similar to the hamster-passaged Wisc-1 strain. Two other isolates, transmitted more efficiently into hamsters and produced two different PrP-res migration profiles compared to Wisc-1-like PrP-res. Transmission of Norwegian moose and reindeer CWD isolates is ongoing; preliminary results will be presented. Our data indicate the existence of at least five different CWD strains based on transmission properties.
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156. Screening and characterization of unusual sCJD cases in a CWD endemic state in the USA
Yihui Liua, Manuel Camachoa, Wenquan Zoua,b,c, Qingzhong Konga,b,c
aDepartment of Pathology, Case Western Reserve University (CWRU), Cleveland, USA; bDepartment of Neurology, CWRU, Cleveland, OH, USA; cNational Center for Regenerative Medicine, CWRU, Cleveland, USA
CONTACT Qingzhong Kong qxk2@case.edu
ABSTRACT
Background: Chronic wasting disease (CWD) has spread to 26 states in the USA and three provinces in Canada, and it has been detected recently in Norway and Finland. Potential CWD zoonosis is a serious public health concern. It is unclear whether CWD transmission to humans has already occurred. We aim to start to address this question by examining all available sCJD cases from a CWD endemic state in the USA.
Methods: Frozen brain tissues from all available sCJD cases archived in the National Prion Disease Pathology Surveillance Center from a US state that has been significantly impacted by CWD were sampled at five brain regions. These brain samples were subjected to detailed biochemical analysis to look for unusual patterns, characteristics, and/or distribution of PrPSc in comparison with sCJD samples from states that have not detected CWD. Unusual cases are further scrutinized for their clinical presentations, histopathological features, and history of cervid hunting and venison consumption.
Results and Conclusions: We have found some unusual sCJD cases in this CWD endemic state. We will report our preliminary findings on their features. Currently there is no convincing evidence to support a direct link to CWD for any of these unusual sCJD cases.
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the position of the National Prion Disease Pathology Surveillance Center.
Thursday, May 23, 2019
Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts
TEXAS CWD TSE PRION STRAIN UNLIKE ANYTHING EVER SEEN
“Wow,” he said. “Unlike anything we've seen before.”
The prions from the Texas deer were a lot harder to destroy than the ones from the Colorado elk. In fact, the guanidine barely damaged them at all. “We’ve never seen that before in any prion strain, which means that it has a completely different structure than we've ever seen before,” says Zabel. And that suggests that it might be a very different kind of chronic wasting disease. The researchers ran the same test on another Texas deer, with the same results.
One day in late February, in their laboratory in Fort Collins, Colorado, Wagner and Zabel compared the prions from the brains of CWD-infected deer in Texas with those of elk in Colorado. They want to know if the proteins were all mangled in the same way, or not. “If they are different, this would suggest that we have different strain properties, which is evidence as we're building our case that we might have multiple strains of CWD circulating in the U.S.,” says Wagner.
Step one is to see if they’re equally easy to destroy using a chemical called guanidine. The shape of a prion dictates everything, including the way it interacts with an animal’s cells and the ease with which chemicals can unfold it.
“Moment of truth,” said Wagner, as she and Zabel huddled around a computer, waiting for results to come through. When they did, Zabel was surprised.
“Wow,” he said. “Unlike anything we've seen before.”
The prions from the Texas deer were a lot harder to destroy than the ones from the Colorado elk. In fact, the guanidine barely damaged them at all. “We’ve never seen that before in any prion strain, which means that it has a completely different structure than we've ever seen before,” says Zabel. And that suggests that it might be a very different kind of chronic wasting disease. The researchers ran the same test on another Texas deer, with the same results.
Now, these are only the preliminary results from a few animals. Wagner and Zabel have a lot more experiments to do. But if future tests come to the same conclusion, it would support their hypothesis that there are multiple strains of chronic wasting disease out there, all with different origins. That, in turn, could mean that this disease will become even trickier to manage than it already is.
And, Zabel adds, there’s something else. “If it's still evolving, it may still evolve into a form that could potentially, eventually affect humans,” he says.
Zabel is not the only one worried about that possibility.
OSTERHOLM, THE EPIDEMIOLOGIST from Minnesota, is also concerned. He directs the Center for Infectious Disease Research and Policy at the University of Minnesota, and is serving a one-year stint as a “Science Envoy for Health Security” with the U.S. State Department. In February, he told Minnesota lawmakers that when it comes to chronic wasting disease, we are playing with fire. “You are going to hear from people that this is not going to be a problem other than a game farm issue. You're going to hear from people that it's not going to transmit to people, and I hope they're right, but I wouldn't bet on it,” he said. “And if we lose this one and haven’t done all we can do, we will pay a price.”
If that wasn’t warning enough, he added: “Just remember what happened in England.”
SUNDAY, APRIL 14, 2019
Chronic Wasting Disease TSE Prion Strains everything in Texas is bigger, better, and badder
WEDNESDAY, MAY 15, 2019
TAHC CWD TSE Prion Summary Minutes of the 402nd Commission Meeting – 12/11/2018
FRIDAY, APRIL 05, 2019
TPWD CWD Sampling Effort Leads to Proposed Containment Zone Expansion
TUESDAY, MARCH 05, 2019
TAHC CWD TSE PRION AT 144 POSITIVE MINUTES OF THE 401st COMMISSION MEETING Texas Animal Health Commission August 7, 2018
TUESDAY, FEBRUARY 26, 2019
TEXAS CWD TSE PRION CASES RISE TO 144 CASES WITH 1 WILD, 1 BREEDER, AND 1 BREEDER RELEASE
SUNDAY, JUNE 10, 2018
TEXAS SUMMARY MINUTES OF THE 400th COMMISSION MEETING CWD TSE PRION TAHC April 17, 2018
SATURDAY, DECEMBER 02, 2017
TEXAS TAHC CWD TSE PRION Trace Herds INs and OUTs Summary Minutes of the 399th and 398th Commission Meeting – 8/22/2017 5/9/2017
TEXAS BREEDER DEER ESCAPEE WITH CWD IN THE WILD, or so the genetics would show?
apparently, no ID though. tell me it ain't so please...
23:00 minute mark
''Free Ranging Deer, Dr. Deyoung looked at Genetics of this free ranging deer and what he found was, that the genetics on this deer were more similar to captive deer, than the free ranging population, but he did not see a significant connection to any one captive facility that he analyzed, so we believe, Ahhhhhh, this animal had some captive ahhh, whatnot.''
*** Hartley County Sheep with Scrapie, and CWD in Hartley county ???
*** Friday, April 22, 2016
*** Texas Scrapie Confirmed in a Hartley County Sheep where CWD was detected in a Mule Deer
CWD TSE PRION PAYING TO PLAY PROGRAM $$$
SUNDAY, MAY 14, 2017
85th Legislative Session 2017 AND THE TEXAS TWO STEP Chronic Wasting Disease CWD TSE Prion, and paying to play
Wednesday, May 04, 2016
TPWD proposes the repeal of §§65.90 -65.94 and new §§65.90 -65.99 Concerning Chronic Wasting Disease - Movement of Deer Singeltary Comment Submission
TUESDAY, DECEMBER 16, 2014
Texas 84th Legislature 2015 H.R. No. 2597 Kuempel Deer Breeding Industry TAHC TPWD CWD TSE PRION
SUNDAY, DECEMBER 14, 2014
TEXAS 84th Legislature commencing this January, deer breeders are expected to advocate for bills that will seek to further deregulate their industry
TEXAS HISTORY OF CWD Singeltary telling TAHC, that CWD was waltzing into Texas from WSMR around Trans Pecos region, starting around 2001, 2002, and every year, there after, until New Mexico finally shamed TAHC et al to test where i had been telling them to test for a decade. 2012 cwd was detected first right there where i had been trying to tell TAHC for 10 years.
***> Singeltary on Texas Chronic Wasting Disease CWD TSE Prion History <***
THURSDAY, OCTOBER 04, 2018
Cervid to human prion transmission 5R01NS088604-04 Update
MONDAY, APRIL 01, 2019
PUBLIC HEALTH U of M launches Chronic Wasting Disease Program to address potential health crisis
MONDAY, FEBRUARY 25, 2019
MAD DOGS AND ENGLISHMEN BSE, SCRAPIE, CWD, CJD, TSE PRION A REVIEW 2019
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
8:58 AM
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