P169 Low levels of classical BSE infectivity in rendered fat tissue
Dr. Christine Fast1, Dr. Markus Keller2, Dr. Ute Ziegler3, Prof. Dr. Martin Groschup4 1Friedrich-Loeffler-Institut, Greifswald, Germany, 2Friedrich-Loeffler-Institut, Greifswald, Germany, 3Friedrich-Loeffler-Institut, Greifswald, Germany, 4Friedrich-Loeffler-Institut, Greifswald, Germany
Aims: Specified Risk Materials (SRM) are the animal tissues potentially containing the highest levels of Bovine Spongiform Encephalopathy (BSE) prions; and their removal is the most important consumer protection measure against BSE. BSE infectivity in the mesentery fat is most likely associated with embedded nervous tissue. To date, it is unclear if contamination of the rendered fat could have occurred during tallow production at a slaughterhouse.
Methods: Samples were taken from five cattle originating from the German BSE pathogenesis study. Two animals were at preclinical, one at late preclinical and one animal at clinical stage of disease; one control animal was included. For all cattle, mouse bioassay results for the celiac and mesenteric ganglion complex (CMGC) were generated previously, showing either no, mild, moderate or substantial infectivity loads. Fat was rendered from CMGC samples embedded in mesentery fat by incubating for 20 minutes at 95°C, according to standard tallow production methods. Subsequently, the melted fat was 1:5 diluted in physiological saline and thoroughly vortexed. The liquid fat was cleaned by a short centrifugation at 10.000 rpm. Finally, 7-12 bovine prion protein overexpressing transgenic mice (Tgbov XV) were i.c. inoculated with 25-30 μl of the supernatant. Mice were sacrificed after 730 days or when showing clinical symptoms and mouse brains were subsequently examined by biochemical and immunohistochemical methods.
Results: Neither the control and the preclinical nor the late preclinical animals showed signs of infectivity in mouse bioassay of the fat samples after up to 730 days p.i. In contrast, low levels of infectivity were detected in the fat of the clinical animal as one mouse displayed a clear accumulation of pathological prion protein in the brain after an incubation period of 598 days p.i.
Conclusions: Our results clearly indicate the potential contamination of melted mesenteric fat by embedded nervous structures during standard tallow production. However, the BSE infectivity level was weak and detectable only in the fat rendered from one sample with documented high infectivity load in the ganglion itself (Kaatz et al. 2012). Albeit, this study is not representative as only one clinical animal was included, it provides a proof of principle. A broader examination would allow a better insight into temporal and spatial distribution pattern of BSE infectivity in rendered fat tissues of different origins.Such estimates have a critical role in qualitative and quantitative risk assessments and in providing advice on the designation and removal of certain SRM tissues.
=====
P68 Eliminating infectivity of bovine spongiform encephalopathy agent by ashing treatment
Dr. Yuichi Matsuura1, Dr. Yuichi Murayama1, Dr. Hiroyuki Okada1, Dr Takashi Yokoyama1, Professor Tetsuyuki Kitamoto2, Professor Shirou Mohri2 1National Institute of Animal Health, NARO, Tsukuba, Japan, 2Tohoku University Graduate School of Medicine, Sendai, Japan
Aims: Bovine spongiform encephalopathy (BSE) is a zoonosis caused by eating and feeding of materials containing the infectious agent. It is known to be resistant to conventional physical and chemical treatments. In particular, heating treatments are extremely ineffective methods for decontamination. The infectivity of BSE agent survives even after wet-heating treatment at 134°C for up to 2 hours or 150°C for 20 minutes and scrapie survives after dry-heating at 600°C for 15 minutes. The aim of this study is to clarify infectivity of BSE agents after ashing treatment by dry-heating.
Methods: The macerate of pooled spinal code (PSC) of four cattle affected with classical BSE agent were treated by dry-heating at 150°C, 200°C, 400°C, 600°C, 800°C and 1000°C in crucibles for 20 minutes. This experiment was performed in triplicate independently as the same conditions. To detect surviving BSE infectivity in PSC after dry-heating, following procedures were invoked.
(1) The seeding activity of PSC samples after dry-heating were examined by protein misfolding cyclic amplification (PMCA) in duplicate of each sample.
(2) In bioassay of PSC samples, transgenic mouse expressing bovine prion protein gene were used as previous report. The most sensitive bioassay of mouse is to detect transmissibility of the disease after intracerebral inoculation, however, FDC bioassay, which detects Protease K resistant prion protein (PrPRes) in spleen after intraperitoneal inoculation, was adoptted to avoid dying the mice by poisoning of dry-heated denatured samples in brains directly. The spleens of mice were removed 150 days post intraperitoneal inoculation with dry-heated PSCs. Infectivity in spleen of mice were verified PrPRes by both Western blot analysis and PMCA.
Results:
(1) PrPRes were detected in cattle PSC samples after dry-heating at 200°C, but not at 400°C and more.
(2) PrPRes was detected in the spleens of mice inoculated with PSC treated dry-heating at 150°C and 200°C by Western blotting, but not at 400 °C and more. However, PMCA in the spleen of mice showed that PrPRes amplification in the case of the dry-heating at 200°C and 400°C, but not at 600°C and more.
Conclusions:
In this study, the infectivity of BSE agent was eliminated by the ashing treatment of dry-heating at 600°C and more. Our findings might support to safe disposal of carcasses of cattle with BSE and re-use of meat and born meal with BSE, and to prevention of environmental contamination of transmissible spongiform encephalopathy.
1: J Neurol Neurosurg Psychiatry 1994 Jun;57(6):757-8
Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery.
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of
Neurological Disorders and Stroke, National Institutes of Health,
Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
PMID: 8006664 [PubMed - indexed for MEDLINE]
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
http://www.prion2010.org/.../prion_2010_program_latest_w...
*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.
TUESDAY, JULY 18, 2017
USDA announces Alabama case of Bovine Spongiform Encephalopathy Alabama
THURSDAY, JULY 20, 2017
USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE animal feeds for ruminants rule, 21 CFR 589.200
SUNDAY, JULY 23, 2017
atypical L-type BASE Bovine Amyloidotic Spongiform Encephalopathy BSE TSE PRION
SUNDAY, JULY 23, 2017
Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy
Saturday, July 23, 2016
BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION SURVEILLANCE, TESTING, AND SRM REMOVAL UNITED STATE OF AMERICA UPDATE JULY 2016
Tuesday, July 26, 2016
Atypical Bovine Spongiform Encephalopathy BSE TSE Prion UPDATE JULY 2016
Monday, June 20, 2016
Specified Risk Materials SRMs BSE TSE Prion Program
THURSDAY, JULY 13, 2017
EFSA BSE Sixty cases of mad cow disease since 2001 breached feed ban likely the cause
Scientists investigate origin of isolated BSE cases
SATURDAY, JULY 29, 2017
Risk Advisory Opinion: Potential Human Health Risks from Chronic Wasting Disease CFIA, PHAC, HC (HPFB and FNIHB), INAC, Parks Canada, ECCC and AAFC
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
Subject: PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS VIDEO
PRION 2017 CONFERENCE DECIPHERING NEURODEGENERATIVE DISORDERS
PRION 2017 CONFERENCE VIDEO
Chronic Wasting Disease CWD TSE Prion to Humans, who makes that final call, when, or, has it already happened?
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
TUESDAY, JULY 04, 2017
*** PRION 2017 CONFERENCE ABSTRACTS ON CHRONIC WASTING DISEASE CWD TSE PRION ***
TUESDAY, JUNE 13, 2017
PRION 2017 CONFERENCE ABSTRACT Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD
URINE
SUNDAY, JULY 16, 2017
*** Temporal patterns of chronic wasting disease prion excretion in three cervid species ***
WEDNESDAY, JULY 26, 2017
Chronic wasting disease continues to spread Disease of cervids causing local population declines
TUESDAY, JULY 18, 2017
MINK FARMING USA TRANSMISSIBLE MINK ENCEPHALOPATHY TSE PRION DISEASE SURVEILLANCE AND TESTING
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
TUESDAY, MARCH 28, 2017
*** Passage of scrapie to deer results in a new phenotype upon return passage to sheep ***
SPONTANEOUS ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY
***Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.***
MONDAY, JULY 17, 2017
National Scrapie Eradication Program May 2017 Monthly Report Fiscal Year 2017
2001 FDA CJD TSE Prion Singeltary Submission
*** U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL
Jan. 9, 2001
THURSDAY, JUNE 22, 2017
World Organisation for Animal Health (OIE) to establish liaison office in College Station, Texas
NEEDLESS CONFLICT
WEDNESDAY, JULY 26, 2017
APHIS USDA Emerging Animal Disease Preparedness and Response Plan July 2017
Friday, January 10, 2014
vpspr, sgss, sffi, TSE, an iatrogenic by-product of gss, ffi, familial type prion disease, what it ???
THURSDAY, JULY 13, 2017
TEXAS CREUTZFELDT JAKOB DISEASE CJD TSE PRION
National Prion Center could lose all funding just as concern about CWD jumping to humans rises
SATURDAY, JULY 15, 2017
*** National Prion Center could lose all funding just as concern about CWD jumping to humans rises
SATURDAY, JULY 22, 2017
Why the U.S. Needs to Continue Prion Disease Surveillance, instead of reducing funding to zero
Terry S. Singeltary Sr.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.