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Humic substances interfere with detection of pathogenic prion protein

October 31, 2013

Studies examining the persistence of prions (the etiological agent of transmissible spongiform encephalopathies) in soil require accurate quantification of pathogenic prion protein (PrPTSE) extracted from or in the presence of soil particles. Here, we demonstrate that natural organic matter (NOM) in soil impacts PrPTSE detection by immunoblotting. Methods commonly used to extract PrPTSE from soils release substantial amounts of NOM, and NOM inhibited PrPTSE immunoblot signal. The degree of immunoblot interference increased with increasing NOM concentration and decreasing NOM polarity. Humic substances affected immunoblot detection of prion protein from both deer and hamsters. We also establish that after interaction with humic acid, PrPTSE remains infectious to hamsters inoculated intracerebrally, and humic acid appeared to slow disease progression. These results provide evidence for interactions between PrPTSE and humic substances that influence both accurate measurement of PrPTSE in soil and disease transmission.

Publication Year 2014
Title Humic substances interfere with detection of pathogenic prion protein
DOI 10.1016/j.soilbio.2013.10.005
Authors Christen B. Smith, Clarissa J. Booth, Tyler J. Wadzinski, Giuseppe Legname, Rick Chappell, Christopher J. Johnson, Joel A. Pedersen
Publication Type Article
Publication Subtype Journal Article
Series Title Soil Biology and Biochemistry
Index ID 70048736
Record Source USGS Publications Warehouse
USGS Organization National Wildlife Health Center