NR AXWP
AU Smith,A.J.; Fernie,K.; Somerville,R.A.
TI Environmental Persistence of TSEs - Extraction of PrPsc from Soil
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Epidemiology, Risk Assessment and Transmission P04.08
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Background: There are concerns about the potential spread of transmissible spongiform encephalopathies (TSEs) by environmental routes following, for example, burial of infected carcasses or the disposal of waste water. The extent to which TSE infectivity survives or is disseminated within soil and soil water is unclear as is the likelihood of ensuing infection.
Aim: As part of this environmental project, soil samples are being collected from lysimeters containing either infected bovine heads or boluses of infectivity. The aim of this experiment is to devise a method for the extraction of PrPsc from soil and examines the interaction between soil and its components and TSE infectivity.
Methods: Samples from two soil types (clay and sandy loam) were spiked with known amounts of TSE infected brain homogenate and subjected to various extraction methods including combinations of freeze/thaw, boiling, sonication and mixing with various solvents and detergents. Any recovery was determined on western blot using PrPsc as a surrogate marker for the presence of TSE infectivity.
Results: These experiments have shown that PrPsc binds strongly to both sandy and clay soil, and to pure sand (quartz). Elution from quartz and the soils was only achieved in the presence of the detergent sarkosyl, and in the case of clay soil, satisfactory elution was only achieved if PrPsc was digested with proteinase K. This finding suggests that components in clay soil may bind differently to PrP than those of sandy soil, and that the N-terminal domain of PrP is involved in this binding.
Conclusion: These results form the basis of a method for the extraction of PrPsc from soil and will be used to assay samples from a large scale lysimeter experiment. Samples testing positive for the presence of PrPsc will be selected for bioassay in mice. Results to date suggest that TSE infectivity may bind strongly to soil components and could therefore persist in the environment for long periods of time.
AD A. Smith, Karen Fernie, R. Somerville, Neuropathogenesis Unit, UK
SP englisch
PO Schottland