Specified Risk Material Research Articles

Biodegradation of bovine spongiform encephalopathy prions in compost

To reduce the transmission risk of bovine spongiform encephalopathy prions (PrPBSE), specified risk materials (SRM) that can harbour PrPBSE are prevented from entering the feed and food chains. As composting is one approach to disposing of SRM, we investigated the inactivation of PrPBSE in lab-scale composters over 28 days and in bin composters over 106–120 days. Lab-scale composting was conducted using 45 kg of feedlot manure with and without chicken feathers. Based on protein misfolding cyclic amplification (PMCA), after 28 days of composting, PrPBSE seeding activity was reduced by 3–4 log10 with feathers and 3 log10 without. Bin composters were constructed using ~ 2200 kg feedlot manure and repeated in 2017 and 2018. PMCA results showed that seeding activity of PrPBSE was reduced by 1–2 log10 in the centre, but only by 1 log10 in the bottom of bin composters. Subsequent assessment by transgenic (Tgbov XV) mouse bioassay confirmed a similar reduction in PrPBSE infectivity. Enrichment for proteolytic microorganisms through the addition of feathers to compost could enhance PrPBSE degradation. In addition to temperature, other factors including varying concentrations of PrPBSE and the nature of proteolytic microbial populations may be responsible for differential degradation of PrPBSE during composting.

Ruminant-Waste Protein Hydrolysates and Their Derivatives as a Bio-Flocculant for Oil Sands Tailing Management.

Reclamation of tailings ponds is a critical issue for the oil industry. After years of consolidation, the slurry in tailings ponds, also known as fluid fine tailings, is mainly comprised of residual bitumen, water, and fine clay particles. To reclaim the lands that these ponds occupy, separation of the solid particles from the liquid phase is necessary to facilitate water removal and recycling. Traditionally, synthetic polymers have been used as flocculants to facilitate this process, but they can have negative environmental consequences. The use of biological polymers may provide a more environmentally friendly approach to flocculation, and eventual soil remediation, due to their natural biodegradability. Peptides derived from specified risk materials (SRM), a proteinaceous waste stream derived from the rendering industry, were investigated to assess their viability for this application. While these peptides could achieve >50% settling within 3 h in bench-scale settling tests using kaolinite tailings, crosslinking peptides with glutaraldehyde greatly improved their flocculation performance, leading to a >50% settling in only 10 min. Settling experiments using materials obtained through different reactant ratios during crosslinking identified a local optimum molar reactant ratio of 1:32 (peptide amino groups to glutaraldehyde aldehyde groups), resulting in 81.6% settling after 48 h. Taken together, these data highlight the novelty of crosslinking waste-derived peptides with glutaraldehyde to generate a value-added bioflocculant with potential for tailings ponds consolidation.

Using Specified Risk Materials-Based Peptides for Oil Sands Fluid Fine Tailings Management.

Fluid fine tailings are produced in huge quantities by Canada’s mined oil sands industry. Due to the high colloidal stability of the contained fine solids, settling of fluid fine tailings can take hundreds of years, making the entrapped water unavailable and posing challenges to public health and the environment. This study focuses on developing value-added aggregation agents from specified risk materials (SRM), a waste protein stream from slaughterhouse industries, to achieve an improved separation of fluid fine tailings into free water and solids. Settling results using synthetic kaolinite slurries demonstrated that, though not as effective as hydrolyzed polyacrylamide, a commercial flocculant, the use of SRM-derived peptides enabled a 2-3-fold faster initial settling rate than the blank control. The pH of synthetic kaolinite tailings was observed to be slightly reduced with increasing peptides dosage in the test range (10–50 kg/ton). The experiments on diluted fluid fine tailings (as a representation of real oil sands tailings) demonstrated an optimum peptides dosage of 14 kg/ton, which resulted in a 4-fold faster initial settling rate compared to the untreated tailings. Overall, this study demonstrates the novelty and feasibility of using SRM-peptides to address intractable oil sands fluid tailings.

Valorizing Biowaste for Wastewater Treatment: Dewatering Sludges Using Specified Risk Material-Based Flocculants for Industrial Sustainability

Sludges, particularly clay-enriched fluid tailings, are major waste streams disposed from mining and mineral processing industries. To improve the separation of sludges into water and stackable solids, a novel flocculant was developed in this study using peptides from specified risk materials (SRMs), a proteinaceous waste from animal rendering industries; the synthesis was accomplished with polyamidoamine epichlorohydrin (PAE) in a one-pot aqueous reaction. Settling tests using standard kaolinite suspensions showed that compared to a petrochemical-based flocculant (hydrolyzed polyacrylamide, HPAM) widely used in the current mining industry, the SRM-based flocculant achieved a similar settling rate but a more complete ultimate dewatering (sediment volume reduced by 47.5%). Unlike HPAM, the performance of the novel flocculant did not require gypsum, a common industrial processing aid that could be detrimental to downstream processing. Interfacial and particle size analyses revealed that the peptide–PAE materials adsorbed at kaolinite surfaces through electrostatic interactions, reduced the fine solids’ net surface charge (ζ from −40 to −15 mV), and facilitated rapid aggregations of these highly suspended solids. Overall, this proof-of-concept study demonstrates the great potential of using a waste protein-based flocculant to address intractable waste sludge challenges for industrial sustainability as well as reduced environmental footprints.

Cross-Linking of Thermally Hydrolyzed Specified Risk Materials with Epoxidized Poly (Vinyl Alcohol) for Tackifier Applications

Prions have been identified as the infection source for bovine spongiform encephalopathy or ‘mad cow disease’. Safety concerns relating to this disease have led to strict feed regulations for specified risk materials (SRMs) in North America, which are characterized as the tissues in cattle where prions are likely to concentrate. As one of the approved SRM disposal methods, thermal hydrolysis converts proteinaceous materials, including prions into non-infective peptides, which have been examined for incorporation into a variety of value-added applications. Here, we describe the bio-conversion of SRM-derived peptides into tackifiers for hydro-mulch applications. Tackifiers are employed in erosion control strategies and help to bind seed and mulch to eroded areas to promote the restoration of vegetation. In this study, epoxidized poly (vinyl alcohol) (PVA) was synthesized and employed for cross-linking of SRM-derived peptides. The reaction conditions and the molar ratio of the reagents applied for the cross-linking reaction were shown to have significant effects on cross-linking behaviour. Furthermore, SRM-derived peptides that were modified with epoxidized PVA displayed viscosity, binding, and moisture maintaining capacity that were comparable to commercially available tackifiers. Hence, this research further strengthens the argument for using SRM-derived peptides as feedstock for sustainable tackifiers development.

Evaluation of thermally hydrolyzed specified risk materials cross-linked with glutaraldehyde for tackifier applications

Specified risk materials (SRMs) are the tissues in cattle where misfolded proteins that cause "mad cow disease" are likely to concentrate, and thus they must be segregated from normal consumption. In this study, peptides derived from SRM hydrolysates were characterized and applied in the development of tackifiers. As one of the key components of a hydro-mulch mixture, tackifiers are employed to bind wood fibres and seeds of plants to the soil in order to facilitate improved rooting. However, sufficient hydrophobicity is also required by tackifiers to prevent diffusion and loss of function when exposed to high levels of moisture. Thus, glutaraldehyde cross-linking was examined to moderate hydrophobicity of SRM-derived peptides. Moreover, other characteristics of the peptides and cross-linked products were assessed and compared with commercial tackifiers. This demonstrated the competitiveness and potential of our SRM bioconversion strategy to produce tackifiers.

Cattle Meat and Offal Imported from the United States of America, Canada and Ireland to Japan (Prions).

Food Safety Commission of Japan (FSCJ) was requested by the Ministry of Health, Labour and Welfare (MHLW) to conduct a risk assessment of cattle meat and offal imported from the United States of America (U.S.A.), Canada and Ireland. FSCJ assessed potential influences on bovine spongiform encephalopathy (BSE) risks to human health in cases of the alteration of cattle age to be allowed to import of cattle meat and offal from the three countries, from the current under 30 months of age to no age limitation, in line with the international standards for mitigating BSE risks. FSCJ judges that the control measures regarding “risks related to slaughtering and meat processing” are appropriately implemented in the three countries. FSCJ concludes that potential variations of BSE risks to human health by removing the age limit on cattle meat and offal excluding specified risk material (SRMs) imported from the three countries in line with the international standards is negligible.

The effects of bolt length on penetration hole characteristics, brain damage and specified-risk material dispersal in finished cattle stunned with a penetrating captive bolt stunner

The purpose of this study was to determine the effect of captive bolt lengths on penetration hole characteristics, brain damage, and specified risk material (SRM) dispersal. Cattle were stunned with a pneumatic captive bolt stunner using: standard (15.2 cm; STRD), medium (16.5 cm; MED), or long (17.8 cm; LON) bolts. Heads (N = 293) and exsanguination blood (N = 103) were collected for analyses. Penetration hole diameter and depth differed by treatment (P ≤ 0.004); both parameters were greatest for LON (P < 0.05). Presence of damage in frontal, parietal, and occipital lobes, olfactory bulb, and collective area including the corpus callosum, fornix and thalamus were impacted by treatment (P < 0.003). Treatment did not impact SRM dispersal (P = 0.33), determined by presence of glial acidic fibrillary protein. Data suggest that bolt length affects both the extent of brain damage and the specific structures damaged but all bolt lengths are successful in causing substantial brain damage and subsequent insensibility.

Pelletization of Torrefied Wood Using a Proteinaceous Binder Developed from Hydrolyzed Specified Risk Materials

Pressing issues such as a growing energy demand and the need for energy diversification, emission reduction, and environmental protection serve as motivation for the utilization of biomass for production of sustainable fuels. However, use of biomass is currently limited due to its high moisture content, relatively low bulk and energy densities, and variability in shape and size, relative to fossil-based fuels such as coal. In recent years, a combination of thermochemical treatment (torrefaction) of biomass and subsequent pelletization has resulted in a renewable fuel that can potentially substitute for coal. However, production of torrefied wood pellets that satisfy fuel quality standards and other logistical requirements typically requires the use of an external binder. Here, we describe the development of a renewable binder from proteinaceous material recovered from specified risk materials (SRM), a negative-value byproduct from the rendering industry. Our binder was developed by co-reacting peptides recovered from hydrolyzed SRM with a polyamidoamine epichlorohydrin (PAE) resin, and then assessed through pelleting trials with a bench-scale continuous operating pelletizer. Torrefied wood pellets generated using peptides-PAE binder at 3% binder level satisfied ISO requirements for durability, higher heating value, and bulk density for TW2a type thermally-treated wood pellets. This proof-of-concept work demonstrates the potential of using an SRM-derived binder to improve the durability of torrefied wood pellets.

Estimating the impact on the food chain of removal of bovine tonsils from specified risk material in Great Britain assuming negligible risk status for bovine spongiform encephalopathy

The earliest estimate for Great Britain (GB) as a whole to achieve negligible risk (NR) status for bovine spongiform encephalopathy (BSE) is 2021. This status allows certain tissues, such as bovine tonsils, to no longer be designated as Specified Risk Materials (SRM). The BSE control model was used to estimate what effect any additional lingual tonsillar material from harvested tongues inadvertently entering the human food chain would have on the amount of infectivity being consumed. Using the baseline model, with tonsils classed as SRM, a mean of 0.08 Bovine Oral (BO) ID50 was estimated to enter the food chain over one year for GB. Under NR status this mean was estimated to increase to 0.83 BO ID50. Whilst this equates to a 10 fold increase in BO ID50 the amount is still small due to the very low likelihood of infected animals being present in the 2017 healthy slaughter population. There are a number of assumptions made within the model, namely, the amount of lingual tonsil inadvertently entering the food chain, and the infectivity titre within this particular tonsillar material.

Estimating the impact on food and edible materials of changing scrapie control measures: The scrapie control model

Multiple controls established during the bovine spongiform encephalopathy (BSE) epidemic were not solely applied to BSE in cattle, but were implemented for scrapie in sheep and goats due to concerns over the occurrence of BSE in sheep. In the absence of BSE in sheep being observed, control measures for prion diseases are now being evaluated to ensure they remain proportionate to risk. This risk assessment, aims to estimate, by use of stochastic simulation, the impact of reducing controls for Specified Risk Materials (SRM) from sheep at abattoir. Three scenarios have been included: 1) current list of SRM; 2) brain and spinal cord of adult sheep; and 3) the brain of adult sheep.Results indicate the total amount of infectivity passing through British abattoirs is highest for atypical scrapie with nearly 3,500,000 Ovine Oral (OO) ID50 per year. The majority of this infectivity enters Category 1 waste for incineration, with only 13,000 OO ID50 per year within edible products. Under Scenario 2, an additional 4000 OO ID50 per year would be classified as edible products from the lifting of restrictions on the distal ileum of adult sheep. However, if SRM removal was limited to brain, an additional 110,000 OO ID50 per year would be permitted into edible products with the lifting of restrictions on the spinal cord of adult sheep.For classical scrapie, there is a mean estimate of infectivity of 30,000 OO ID50 per year at abattoir. This is lower than for atypical scrapie due to the lower occurrence of this disease in Great Britain. However, more infectivity is destined to reach the food chain as the disease is peripherally distributed in the carcase. The highest contributor to the total amount of infectivity consumed per year is the intestines (duodenum and jejunum). If SRM removal is limited to the brain and spinal cord of sheep over 12 months of age, there is an approximate mean increase from 19,000 to 21,000 OO ID50 per year diverted to edible products. If the SRM list is restricted to brain only, this increases to over 23,000 OO ID50 per year.For the potential of sheep-BSE, there is a very low estimate of 29 OO ID50 per year in total from carcases entering abattoir, due to the potential very rare occurrence of this disease. Given changes in SRM regulations there is a change of an additional 4 OO ID50 per year being diverted to edible products.

Updated quantitative risk assessment (QRA) of the BSE risk posed by processed animal protein (PAP).

EFSA was requested: to assess the impact of a proposed quantitative real‐time polymerase chain reaction (qPCR) ‘technical zero’ on the limit of detection of official controls for constituents of ruminant origin in feed, to review and update the 2011 QRA, and to estimate the cattle bovine spongiform encephalopathy (BSE) risk posed by the contamination of feed with BSE‐infected bovine‐derived processed animal protein (PAP), should pig PAP be re‐authorised in poultry feed and vice versa, using both light microscopy and ruminant qPCR methods, and action limits of 100, 150, 200, 250 and 300 DNA copies. The current qPCR cannot discriminate between legitimately added bovine material and unauthorised contamination, or determine if any detected ruminant material is associated with BSE infectivity. The sensitivity of the surveillance for the detection of material of ruminant origin in feed is currently limited due to the heterogeneous distribution of the material, practicalities of sampling and test performance. A ‘technical zero’ will further reduce it. The updated model estimated a total BSE infectivity four times lower than that estimated in 2011, with less than one new case of BSE expected to arise each year. In the hypothetical scenario of a whole carcass of an infected cow entering the feed chain without any removal of specified risk material (SRM) or reduction of BSE infectivity via rendering, up to four new cases of BSE could be expected at the upper 95th percentile. A second model estimated that at least half of the feed containing material of ruminant origin will not be detected or removed from the feed chain, if an interpretation cut‐off point of 100 DNA copies or more is applied. If the probability of a contaminated feed sample increased to 5%, with an interpretation cut‐off point of 300 DNA copies, there would be a fourfold increase in the proportion of all produced feed that is contaminated but not detected.

Development of hydrolysed protein-based plywood adhesive from slaughterhouse waste: effect of chemical modification of hydrolysed protein on moisture resistance of formulated adhesives.

Specified risk materials (SRM) constitute the proteinaceous waste of slaughterhouses and are currently being disposed off either by incineration or by land filling. Over the last few years, our efforts have focused on developing technology platforms for deployment of this renewable resource for various value-added industrial applications. This report describes a technology for utilization of SRM for the development of an environmentally friendly plywood adhesive with an improved water resistance property. The feedstock (SRM) was first thermally hydrolysed according to a standard protocol, and the hydrolysed protein fragments (peptides) were recovered from the hydrolysate. The recovered peptides were chemically modified through esterification reaction using ethanol, and then chemically crosslinked with polyamideamine-epichlorohydrin (PAE) resin to develop a wood adhesive system. Plywood specimens were then developed using the peptides–PAE resin-based adhesive. The effects of crosslinking time, solid content of the adhesive formulation, ratio of peptides and crosslinking agent in the formulation, and curing conditions of specimen preparation on lap shear strength of resulting plywood specimens were systematically evaluated. Despite the hydrophilic nature of hydrolysed protein fragments, the peptides–PAE resin formulations exhibited remarkable water resistance property after curing. Capping of polar carboxyl groups of peptides by converting them to esters further improved the water resistance property of this adhesive system. Under the optimum conditions of adhesive preparation and curing, the ethyl ester derivative of peptides and PAE resin-based formulations resulted in plywood specimens having comparable dry as well as soaked shear strengths to those of commercial phenol formaldehyde resin.

Examination of a Captive Bolt Stunner with 3 Different Bolt Lengths on Cattle Brain Damage and Specified Risk Materials Dispersion

ObjectivesCaptive bolt stunning is a standard and effective method of rendering cattle unconscious for slaughter. An unrecoverable penetrating stun is ensured by correct placement of the captive bolt stunner. The purpose of this study was to determine the effect of different bolt lengths on sustained brain damage and presence of specified risk materials (SRM) in blood of Holstein and non-Holstein cattle. It was hypothesized that brain damage and SRM dispersion would not differ based on bolt length or breed type.Materials and MethodsThe study was designed as a randomized unbalanced block design. Test day served as a block and the experimental unit was animal. Data were analyzed with SAS (SAS Inst. Inc., Cary, NC) using a paired t test. Each collection was assigned 1 of 3 lengths; control (CON; 15.2 cm), medium (MED; 16.5 cm), or long (LON; 17.8 cm). All animals sampled were less than 30 mo of age. Blood was randomly sampled immediately following the start of exsanguination from 33 animals per treatment, with an equal split of Holstein and non-Holstein breed type. Blood samples were sent to IEH-Warren Analytical Laboratory (IEH, Greeley, CO) where the Colorado State University fluorescent enzyme-linked immunosorbent assay (F-ELISA) was conducted for detection of glial proteins. For brain damage assessment, 292 heads were randomly sampled across 3 collection periods, with an equal split between non-Holstein and Holstein breed type. Heads were collected, chilled, and brought to the Necropsy Laboratory (Colorado State University, Veterinary Teaching Hospital, Fort Collins, CO) for splitting and damage analysis. Skulls were split with a bandsaw through the median plane of the captive bolt penetration tract. Brains were photographed and assessed for damage to the frontal lobe (FL), parietal lobe (PL), occipital lobe (OL), olfactory bulb (OB), hypothalamus (HYP), corpus callosum (CC), fornix (FOR), and the thalamus (THAL). Brain structure disruption was determined with a graphic overlay along the median plane; each structure was recorded as either damaged or non-damaged. Additionally, evidence of double knocking (DK) or skull plate fragments in the brain tissue (BC) were recorded.ResultsThe Colorado State University F-ELISA found that 97% of the CON blood samples were negative, 94% of the MED blood samples were negative, and 100% of the LON blood samples were negative. The level of brain damage did not differ between breed type for any structure measured (P = 0.607). The amount of brain damage was statistically different between CON and LON for FL, OL, and THAL (P = 0.004, P = 0.025, and P = 0.002, respectively). The FL, OL, CC, and THAL differed between MED and LON (P = 0.022, P = 0.043, P = 0.043, and P = 0.002, respectively). Comparisons between CON and MED showed that only FL damage differed (P = 0.033). The percentage of DK and BC in brain tissue did not differ based on treatment or breed type (P = 0.399, P = 0.311). The brainstem was not disrupted for any of the treatments.ConclusionThere was sufficient evidence that differing bolt lengths affect the amount of brain damage to the skull and brain structures. Additionally, there was minimal evidence to support that changes in SRM dispersal occurred due to bolt length. Further work is required to determine how bolt length could affect SRM transmission in older animals.

牛海綿状脳症（BSE）国内対策の見直しに係る食品健康影響評価（健康と畜牛のBSE検査の廃止）

FSCJ conducted assessments on human health risk associated with Bovine Spongiform Encephalopathy (BSE) in relation to the proposed revision of the domestic measures, in response to requests from the Ministry of Health, Labour and Welfare (MHLW). Using the findings obtained from published documents and reference materials /documents submitted by the MHWL, FSCJ first completed the risk assessment of the limit of cattle age for BSE testing, and subsequently will conduct the assessment of definition of Specified Risk Materials (SRMs).

A Bayesian back-calculation method to estimate the risk of bovine spongiform encephalopathy (BSE) in Canada during the period 1996–2011

ABSTRACTSeventeen typical cases of bovine spongiform encephalopathy (BSE) were detected in Canada the period of 2003-2011. The clinical incidence of BSE was censored by early slaughter, death, or exportation of infected cattle due to the long incubation period of BSE disease. The aim of this study was to estimate the infection incidence of BSE in birth cohorts during 1996–2004 and project infection frequency through to 2007. An estimate of the number of asymptomatic infected cattle slaughtered for human consumption is also provided. The number of incident, asymptomatic cases was assumed to follow a Poisson process. A Bayesian back-calculation approach was used to project the risk of contracting BSE in those birth cohorts. Model parameters and inputs were taken from scientific literature and governmental data sources. The projected number of infected cattle in birth cohorts spanning the period 1996–2007 was 492, with median 95% credible interval 258–830. If the requirement to remove specified risk material (SRM) from cattle prior to entering the food chain was not in place, the predicted number of slaughtered infected in the human food chain from 1996–2010 was 298, with a 95% credible interval 156–500. The magnitude of the BSE epidemic in Canada for 1996–2007 birth cohorts was estimated to be approximately 28-fold higher than the number of clinical cases detected through to October 2011. Although some of those cattle were slaughtered for human consumption, the requirement of SRM removal may have prevented most of the infectious material from entering the food chain.

Enhancing the Adhesive Strength of a Plywood Adhesive Developed from Hydrolyzed Specified Risk Materials.

The current production of wood composites relies mostly on formaldehyde-based adhesives such as urea formaldehyde (UF) and phenol formaldehyde (PF) resins. As these resins are produced from non-renewable resources, and there are some ongoing issues with possible health hazard due to formaldehyde emission from such products, the purpose of this research was to develop a formaldehyde-free plywood adhesive utilizing waste protein as a renewable feedstock. The feedstock for this work was specified risk material (SRM), which is currently being disposed of either by incineration or by landfilling. In this report, we describe a technology for utilization of SRM for the development of an environmentally friendly plywood adhesive. SRM was thermally hydrolyzed using a Canadian government-approved protocol, and the peptides were recovered from the hydrolyzate. The recovered peptides were chemically crosslinked with polyamidoamine-epichlorohydrin (PAE) resin to develop an adhesive system for bonding of plywood specimens. The effects of crosslinking time, peptides/crosslinking agent ratio, and temperature of hot pressing of plywood specimens on the strength of formulated adhesives were investigated. Formulations containing as much as 78% (wt/wt) peptides met the ASTM (American Society for Testing and Materials) specifications of minimum dry and soaked shear strength requirement for UF resin type adhesives. Under the optimum conditions tested, the peptides–PAE resin-based formulations resulted in plywood specimens having comparable dry as well as soaked shear strength to that of commercial PF resin.

Presence of central nervous system tissues as bovine spongiform encephalopathy specified risk material in Turkish raw meat ball (cig kofte)

Bovine Spongiform Encephalopathy (BSE) is a virulent disease which may infect by affecting the central nervous system (CNS) tissues in cattle and causes degeneration in nerves. Central nervous system tissues such as brain and spinal cord which are classified as specified risk materials (SRMs) are regarded to be main source of infection. The contamination of the meat with the specific risk materials (SRMs) can occur in phases of slaughter, fragmentation of carcass and processing. This study was conducted in order to investigate the existence of CNS tissues in raw meat ball (cig kofte) which is commonly consumed in the Southeastern Region of Turkey, particularly in Sanliurfa. For this purpose, 145 samples of raw meat ball were tested. The enzyme-linked immunosorbent assay (ELISA) kits (Ridascreen risk material 10/5, R-biofarm GmbH) which determine glial fibrillary acidic protein (GFAP) as determinant were used. As a result of the analyses, positivity was detected in 21 of totally 145 samples of raw meat ball (14.48%). 6 (4.14%) of the samples gave low level of positivity (≥ 0.1 standard absorbance), 10 (6.90%) gave medium level of positivity (>0.2 standard absorbance) and 5 (3.45%) gave high level of positivity (≥0.5 standard absorbance). As a consequence, meats are contaminated in any phase of both slaughter and meat production even if accidentally. Regarding this matter, necessary measures should be taken and hygiene rules should be applied.

Application of protein misfolding cyclic amplification to detection of prions in anaerobic digestate

The exceptional physio-chemical resistance of prions to established decontamination procedures poses a challenge to assessing the suitability of applied inactivation methods. Prion detection is limited by the sensitivity level of Western blotting or by the cost and time factors of bioassays. In addition, prion detection assays can be limited by either the unique or complex nature of matrices associated with environmental samples. To investigate anaerobic digestion (AD) as a practical and economical approach for potential conversion of specified risk materials (SRM) into value added products (i.e., renewable energy), challenges associated with detection of prions in a complex matrix need to be overcome to determine potential inactivation. Protein misfolding cyclic amplification (PMCA) assay, with subsequent Western blot visualization, was used to detect prions within the AD matrix. Anaerobic digestate initially inhibited the PMCA reaction and/or Western blot detection. However, at concentrations of ≤1% of anaerobic digestate, 263K scrapie prions could be amplified and semi-quantitatively detected. Infectious 263K prions were also proven to be bioavailable in the presence of high concentrations of digestate (10–90%). Development of the PMCA application to digestate provides extremely valuable insight into the potential degradation and/or fate of prions in complex biological matrices without requiring expensive and time-consuming bioassays.

POSKYTOVÁNÍ NÁHRAD ZA ZTRÁTY SPOJENÉ S VÝSKYTEM BOVINNÍ SPONGIFORMNÍ ENCEFALOPATIE V ČESKÉ REPUBLICE

Since 2001 when the first case of bovine spongiform encephalopathy (BSE) was identified in the Czech Republic, a total of 27 infected cows have been detected. A single outbreak of BSE in 2007 confirms that, in the Czech Republic, the disease incidence has a decreasing trend, which is in agreement with the situation in other EU countries. In order to conrol the disease and in the interests of human health protection, the killing of infected animals and related cohorts (groups of potentially infected animals), as well as eliminaton of specified risk material (SRM) were commenced. To reduce the negative impact of these measures on agricultural production it was possible, on the basis of the Veterinary Act No. 166/1999, to compensate the relevant costs to the farmers involved; these were covered by the Ministry of Finance of the Czech Republic from the budgedary chapter „General Treasury Administration“. Between the outbreak in 2001 and 2007, a total of 1 181 296 cows were examined and, based on the finding of 27 BSE-positive animals, 3 994 cows were subsequently slaughtered. BSE exa­mi­na­tion, killing and decontamination costs amounted to 18.9 million CZK, compensation costs for killed animals reached almost 163.9 million CZK and compensation for unaccomplished production accounted for over 13.6 million CZK. Together with other additional costs, the total financial compensations paid out during the period of BSE presence were almost 197 million CZK. The findings of this study are discussed and compared with rather sparse information available on the costs related to BSE abroad. The available data suggests that the compensations for BSE-related costs paid to farmers in the Czech Republic were proportional to those in the European Union, USA or Canada.