In Vitro detection of Chronic Wasting Disease (CWD) prions in semen and reproductive tissues of white tailed deer bucks (Odocoileus virginianus
SUNDAY, AUGUST 02, 2015
TEXAS CWD, Have you been ThunderStruck, deer semen, straw bred bucks, super ovulation, and the potential TSE Prion connection, what if?
RESEARCH ARTICLE
In Vitro detection of Chronic Wasting Disease (CWD) prions in semen and reproductive tissues of white tailed deer bucks (Odocoileus virginianus)
Carlos Kramm,Ruben Gomez-Gutierrez,Claudio Soto,Glenn Telling,Tracy Nichols,Rodrigo Morales Published: December 30, 2019https://doi.org/10.1371/journal.pone.0226560
Abstract
Chronic Wasting Disease (CWD) is a prion disease affecting several cervid species. Among them, white-tailed deer (WTD) are of relevance due to their value in farming and game hunting. The exact events involved in CWD transmission in captive and wild animals are still unclear. An unexplored mechanism of CWD spread involves transmissions through germplasm, such as semen. Surprisingly, the presence and load of CWD prions in semen and male sexual tissues from WTD has not been explored. Here, we described the detection of CWD prions in semen and sexual tissues of WTD bucks utilizing the Protein Misfolding Cyclic Amplification (PMCA) technology. Samples were obtained post-mortem from farmed pre-clinical, CWD positive WTD bucks possessing polymorphisms at position 96 of the PRNP gene. Our results show that overall CWD detection in these samples had a sensitivity of 59.3%, with a specificity of 97.2%. The data indicate that the presence of CWD prions in male sexual organs and fluids is prevalent in late stage, pre-clinical, CWD-infected WTD (80%-100% of the animals depending on the sample type analyzed). Our findings reveal the presence of CWD prions in semen and sexual tissues of prion infected WTD bucks. Future studies will be necessary to determine whether sexual contact and/or artificial inseminations are plausible means of CWD transmission in susceptible animal species.
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Discussion Our results show, for the first time, the presence of CWD prions in semen and reproductive tissues of CWD-infected WTD bucks. Our results are relevant considering that samples were obtained from naturally infected animals, in which prion incubation periods and routes of exposure are unknown. These results shed light on PrPsc trafficking within the body and indicate that live animal studies are warranted to understand the potential role of semen in CWD transmission. From the detection perspective, our results show a similar degree of efficiency when compared to blood detection using similar methods. Overall detection in CWD positive samples was 59.3%. This ratio increased to 93.3% when only samples from the late CWD pre-clinical stage were considered. Prion detection in testes stroma and epididymides behaved similarly as to semen, suggesting that prion tropism to male sexual related tissues and fluids occurs only at late stages. It is important to note that sample size for this study was considerably lower compared to the previous study evaluating blood samples [17].
Considering our previous data on CWD prion detection in blood [17], it is valid to question whether our positive PMCA results in male reproductive tissues and semen are due to this fluid. It is important to mention that the semen samples used in this study did not have noticeable blood contamination by visual examination. With regard to testes and epididymis, the presence of blood is undeniable. Nevertheless, and as described in Fig 4, components present in these samples strongly inhibit PMCA performance and negate the possible effect of blood in our results.
Some unexpected results were observed in this study (S1 Table). One of them involves one animal at late CWD pre-symptomatic stage that was PMCA positive in semen and epididymis, but negative in testes. Another involves an early pre-symptomatic animal that was CWD positive in testis and epididymis, but negative in semen. This could be explained by the low presence of PrPSc in these samples and the inhibition that testes and epididymis homogenates exerted in PMCA (Fig 4). These two factors could play an important role in our PMCA readouts. In that sense, future analyses of additional and higher number of samples, and tested in multiple replicates, could tell us whether these off-trend cases are caused by technical issues related to the PMCA technology. Another explanation for this behavior could be found in the strain variation displayed by CWD prions [27,29–31]. Prion strains are known to exert different pathological and clinical features in the host, including different tissue tropism [32]. Considering that our samples were obtained from natural CWD cases, it could be possible that animals were infected with prion isolates targeting the reproductive system of bucks in different patterns. This idea acquire additional support in the fact that animals included in this study displayed different polymorphic versions of the prion protein (an additional source of prion strain variation[33]). Another unexpected result came from one animal in the CWD-free group that resulted in positive PrPSc detection in epididymis. The simplest explanation for this result is cross-contamination. Although samples were carefully collected to avoid contamination, this is always a possibility when working with field collected specimens. Another possibility is that our PMCA format detected prions in these samples earlier than IHC in lymph nodes. The contribution of all the previously mentioned variables in sexual tissue–PrPSc detection should be pursued in carefully designed future studies.
In terms of disease transmission, the presence of prions in semen begs the question on whether sexual contact is plausible route of CWD transmission. A previous report showed that semen collected from rams at pre-clinical and clinical stages of prion disease did not infect scrapie-susceptible mice [34]. Our previous results in Syrian hamsters showed that sexual exposure of naïve females to 263K infected males was ineffective in transmitting disease [35]. Maternal transmission has also be presented as a viable mode of CWD transmission to offspring. Evidence derived from scrapie-infected sheep and experimentally infected muntjac deer provides direct evidence that offspring from infected dams and ewes are at higher risk of developing prion disease [16,36]. Considering the results presented in this article, the risk of CWD transmission via semen cannot be dismiss without further inquiry. It is important to note that some semen samples tested in the current report showed PrPSc presence after only one PMCA round, suggesting that PrPSc content in semen of some animals may be relatively high. This is particularly relevant considering that tissues from male sexual organs inhibited PMCA performance. It remains unclear if vaginal exposure to CWD prions in semen is an effective route of transmission.
In summary, our results confirm the presence of CWD prions in semen and male sexual tissues in CWD-infected WTD. Future experiments in actual deer will determine whether CWD can be transmitted by breeding practices including sexual contacts or artificial inseminations. Infectivity studies in transgenic mice underway in our laboratory will determine the infectivity titers of some of the samples described in this study.
In Vitro detection of Chronic Wasting Disease (CWD) prions in semen and reproductive tissues of white tailed deer bucks (Odocoileus virginianus Published: December 30, 2019
SUNDAY, AUGUST 02, 2015
TEXAS CWD, Have you been ThunderStruck, deer semen, straw bred bucks, super ovulation, and the potential TSE Prion connection, what if?
http://chronic-wasting-disease.blogspot.com/2015/08/texas-cwd-have-you-been-thunderstruck.html
WEDNESDAY, MARCH 13, 2019
CWD, TSE, PRION, MATERNAL mother to offspring, testes, epididymis, seminal fluid, and blood
Subject: Prion 2019 Conference
See full Prion 2019 Conference Abstracts
see scientific program and follow the cwd studies here;
Thursday, May 23, 2019
Prion 2019 Emerging Concepts CWD, BSE, SCRAPIE, CJD, SCIENTIFIC PROGRAM Schedule and Abstracts
FRIDAY, MAY 24, 2019
Assessing chronic wasting disease strain differences in free-ranging cervids across the United States
MONDAY, MAY 20, 2019
APHIS, USDA, Announces the Finalized Chronic Wasting Disease Herd Certification Program Standards Singeltary Submissions
CWD WEBINAR CWD YESTERDAY! December 11, 2019
Dr. Mckenzie and CIDRAP on CWD TSE Prion
122: Prions and Chronic Wasting Disease with Jason Bartz
Texas CWD Symposium: Transmission by Saliva, Feces, Urine & Blood
the other part, these tissues and things in the body then shed or secrete prions which then are the route to other animals into the environment, so in particular, the things, the secretions that are infectious are salvia, feces, blood and urine. so pretty much anything that comes out of a deer is going to be infectious and potential for transmitting disease.
''On January 21, 2017 a tornado took down thousands of feet of fence for a 420-acre illegal deer enclosure in Lamar County that had been subject to federal and state investigation for illegally importing white-tailed deer into Mississippi from Texas (a CWD positive state). Native deer were free to move on and off the property before all of the deer were able to be tested for CWD. Testing will be made available for a period of three years for CWD on the property and will be available for deer killed within a 5-mile radius of the property on a voluntary basis. ''
Texas Chronic Wasting Disease CWD TSE Prion Symposium 2018 posted January 2019 VIDEO SET 18 CLIPS
See Wisconsin update...terrible news, right after Texas updated map around 5 minute mark...
WISCONSIN CWD CAPTIVE CWD UPDATE VIDEO
cwd update on Wisconsin from Tammy Ryan...
Wyoming CWD Dr. Mary Wood
''first step is admitting you have a problem''
''Wyoming was behind the curve''
wyoming has a problem...
SATURDAY, JANUARY 19, 2019
Texas Chronic Wasting Disease CWD TSE Prion Symposium 2018 posted January 2019 VIDEO SET 18 CLIPS
TEXAS BREEDER DEER ESCAPEE WITH CWD IN THE WILD, or so the genetics would show?
OH NO, please tell me i heard this wrong, a potential Texas captive escapee with cwd in the wild, in an area with positive captive cwd herd?
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.''
Wyoming CWD Dr. Mary Wood
''first step is admitting you have a problem''
''Wyoming was behind the curve''
wyoming has a problem...
the other part, these tissues and things in the body then shed or secrete prions which then are the route to other animals into the environment, so in particular, the things, the secretions that are infectious are salvia, feces, blood and urine. so pretty much anything that comes out of a deer is going to be infectious and potential for transmitting disease.
Texas Chronic Wasting Disease CWD TSE Prion Symposium 2018 posted January 2019 VIDEO SET 18 CLIPS See Wisconsin update...terrible news, right after Texas updated map around 5 minute mark...
SATURDAY, JANUARY 19, 2019
Texas Chronic Wasting Disease CWD TSE Prion Symposium 2018 posted January 2019 VIDEO SET 18 CLIPS
THURSDAY, DECEMBER 19, 2019
TEXAS Val Verde County White-tailed Deer Tests Positive for Chronic Wasting Disease CWD TSE Prion State Positive NOW at 147 Confirmed
FRIDAY, DECEMBER 20, 2019
TEXAS ANIMAL HEALTH COMMISSION EXECUTIVE DIRECTOR ORDER DECLARING A CHRONIC WASTING DISEASE HIGH RISK AREA CONTAINMENT ZONE FOR PORTIONS OF VAL VERDE COUNTY
FRIDAY, DECEMBER 20, 2019
Texas TAHC, Administrative Code, Title 4, Part 2, Chapter 40, Chronic Wasting Disease Amendments Open For Comment beginning December 20, 2019 thru January 20, 2020 Terry Singeltary Comments Submission
SEE UPDATED CWD REPORTS IN THIS FOLLOWING LINK;
TUESDAY, DECEMBER 31, 2019
Missouri MDC TESTS SHOW SEVEN NEW CHRONIC WASTING DISEASE CASES IN SOUTHEAST
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
11:27 AM
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