Scrapie in Mice. The Stability of the Agent to Various Suspending Media, pH and Solvent Extraction

Mould, Dallas L; Am, Dawson; Smith, William D.

doi:10.1016/s0034-5288(18)34749-0

Cited by 26 publications

(7 citation statements)

References 9 publications

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“…NaHCO 3 produced cleaned human bones with a well-preserved surface morphology supporting the in vitro growth and maturation of SaOS-2 cells. However, virus and prion inactivating properties of this treatment are unknown and additional procedures remain to be used [40].…”

Section: Resultsmentioning

confidence: 99%

The influence of processes for the purification of human bone allografts on the matrix surface and cytocompatibility

et al. 2006

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Section: Resultsmentioning

confidence: 99%

The influence of processes for the purification of human bone allografts on the matrix surface and cytocompatibility

et al. 2006

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“…In order to investigate the molecular basis of high acid resistance of infectivity (Mould et al, 1965;Prusiner et al, 1981;Brown et al, 1986), scrapie prion rod isolates from hamster brain and in vitro-generated b-aggregates (Jansen et al, 2001) of the corresponding recombinant prion protein rPrP(90-231) were incubated with hydrochloric acid. The amount of PrP remaining intact after various incubation times, acid concentrations and temperatures was quantified by gel electrophoresis and Western blot.…”

Section: Resultsmentioning

confidence: 99%

“…How can the acid treatment of prion rods be explained in molecular mechanistic terms? Treatment of scrapie-infected brain homogenate or scrapie isolates with 0?3 or 1 M NaOH for 1 h at room temperature inactivates infectivity by at least three orders of magnitude (Mould et al, 1965;Prusiner et al, 1981;Brown et al, 1986). This dramatic effect has been attributed to alkaline hydrolysis of the peptide bonds of PrP and a proportional inactivation of prion infectivity.…”

Section: (Equation 3)mentioning

confidence: 99%

Acid inactivation of prions: efficient at elevated temperature or high acid concentration

Appel

Lucassen

Groschup

et al. 2006

Journal of General Virology

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Scrapie prion rods isolated from hamster and non-infectious aggregates of the corresponding recombinant protein rPrP(90-231) were incubated with hydrochloric acid. The amount of PrP and of infectivity that survived incubation in HCl at varying times, acid concentrations and temperatures was quantified by Western blot densitometry and bioassays, respectively. Prion rods and rPrP aggregates showed similar HCl hydrolysis kinetics of PrP, indicating structural homology. For 1 M HCl and 25 6C, the rate of PrP hydrolysis follows first-order kinetics at 0?014 h "1 ; the rate of infectivity inactivation is 0?54 h "1 . Hydrolysis for 1 h at 25 6C was only slightly proportional toHCl concentration up to 5 M, but complete loss of infectivity and PrP reduction to <2 % was observed at 8 M HCl. The temperature dependence of unhydrolysed PrP, as well as infectivity at 1 M HCl for 1 h, showed a slight decrease up to 45 6C, but a sigmoidal decrease by several orders of magnitude at higher temperatures. The slow hydrolysis of PrP and inactivation of infectivity by acid treatment at room temperature are attributed to solvent inaccessibility of prion rods and rPrP aggregates, respectively. The more effective hydrolysis and inactivation at temperatures above 45 6C are interpreted as thermally induced disaggregation with an activation energy of 50-60 kJ mol "1. Most importantly, infectivity was always inactivated faster or to a higher extent than PrP was hydrolysed at several incubation times, HCl concentrations and temperatures.

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“…As strong alkaline or acidic solutions have the effect of reducing the infectious titre of TSE (Taylor, 2000). Mould et al (1965) reported that at pH 2.1 infectivity was reduced by 0.9 log 10 compared with pH 7.0. Similarly, at pH 10.5 it was reduced by 1 log 10 compared to neutral pH.…”

Section: Alkaline/acidic Treatmentmentioning

confidence: 99%

“…Mould et al. (1965) reported that at pH 2.1 infectivity was reduced by 0.9 log 10 compared with pH 7.0. Similarly, at pH 10.5 it was reduced by 1 log 10 compared to neutral pH.…”

Section: Assessmentmentioning

confidence: 99%

Potential BSE risk posed by the use of ruminant collagen and gelatine in feed for non‐ruminant farmed animals

Koutsoumanis¹,

Allende²,

Bolton³

et al. 2020

EFS2

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EFSA was requested to estimate the cattle bovine spongiform encephalopathy ( BSE ) risk (C‐, L‐ and H‐ BSE ) posed by ruminant collagen and gelatine produced from raw material fit for human consumption, or from material classified as Category 3 animal by‐products ( ABP ), to be used in feed intended for non‐ruminant animals, including aquaculture animals. Three risk pathways ( RP ) were identified by which cattle could be exposed to ruminant feed cross‐contaminated with ruminant collagen or gelatine: 1) recycled former foodstuffs produced in accordance with Regulation ( EC ) No 853/2004 ( RP 1), 2) technological or nutritional additives or 3) compound feed, produced either in accordance with Regulation ( EC ) No 853/2004 ( RP 2a) or Regulation ( EU ) No 142/2011 ( RP 2b). A probabilistic model was developed to estimate the BSE infectivity load measured in cattle oral ID 50 (Co ID 50 )/kg, in the gelatine produced from the bones and hide of one infected animal older than 30 months with clinical BSE (worst‐case scenario). The amount of BSE infectivity (50th percentile estimate) in a member state ( MS ) with negligible risk status was 7.6 × 10 –2 Co ID 50 /kg, and 3.1 × 10 –4 Co ID 50 /kg in a MS with controlled risk status. The assessment considered the potential contamination pathways and the model results (including uncertainties) regarding the current epidemiological situation in the EU and current statutory controls. Given the estimated amount of BSE infectivity to which cattle would be exposed in a single year, and even if all the estimated undetected BSE cases in the EU were used for the production of collagen or gelatine (either using raw materials fit for human consumption or Category 3 ABP raw materials), it was concluded that the probability that no new case of BSE in the cattle population would be generated through any of the three RP is 99–100% (almost certain).

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Scrapie in Mice. The Stability of the Agent to Various Suspending Media, pH and Solvent Extraction

Cited by 26 publications

References 9 publications

The influence of processes for the purification of human bone allografts on the matrix surface and cytocompatibility

The influence of processes for the purification of human bone allografts on the matrix surface and cytocompatibility

Acid inactivation of prions: efficient at elevated temperature or high acid concentration

Potential BSE risk posed by the use of ruminant collagen and gelatine in feed for non‐ruminant farmed animals

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