Identification of the pathological prion protein allotypes in scrapie-infected heterozygous bank voles (Clethrionomys glareolus) by high-performance liquid chromatography-mass spectrometry

Cerebral formation of the pathological isoform of the prion protein (PrP) is a crucial molecular event in prion diseases. The bank vole (Clethrionomys glareolus) is a rodent species highly susceptible to natural scrapie. The PrP gene of bank vole is polymorphic (Met/Ile) at codon 109. Here we show that homozygous 109Met/Met voles have incubation times shorter than heterozygous 109Met/Ile voles after experimental challenge with three different scrapie isolates. An HPLC-MS/MS method was optimized and applied to investigate whether in heterozygous animals both PrP allotypes are able to undergo pathological conversion. The results demonstrate that both allotypes of the prion protein participate to pathological deposition.     

Identification of prion protein genotype in sheep: 11 years of proficiency tests in Italy

Accreditation and Quality Assurance - Scrapie of sheep belongs to a group of fatal neurodegenerative diseases known as prion diseases. Scrapie is a naturally transmissible disease and sheep...     

Real-time polymerase chain reaction approach for quantitation of ruminant-specific DNA to indicate a correlation between DNA amount and meat and bone meal heat treatments

The use of ruminant-derived proteins in ruminant feeds has been banned in both the European Union and the United States to prevent further spread of bovine spongiform encephalopathy. Enforcement of these regulations relies on the ability to identify the presence of prohibited proteins in feed. We developed a quantitative real-time polymerase chain reaction assay for the quantification of ruminant-specific DNA as index of protein content. The assay is based on the amplification of a 117 base pair mitochondrial 16S rRNA DNA gene fragment and an internal positive control (IPC). The use of an IPC permits compensation for differences in DNA extraction efficiency and avoids the occurrence of false-negative results. We demonstrated a decrease in target DNA amount with a difference of 2 logs between meat and bone meal (MBM) treated at 133 degrees and 145 degrees C. Such a difference indicates that bias could occur when DNA-based methods are used for quantitation purposes. Risk management could benefit from future efforts concerning validation of the method for MBM detection in feedstuff and safety evaluation of the use of animal-derived proteins in animal nutrition.