In:
BMC Veterinary Research, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2013-12)
Abstract:
Prions, infectious agents associated with transmissible spongiform encephalopathy, are primarily composed of the misfolded and pathogenic form (PrP Sc ) of the host-encoded prion protein. Because PrP Sc retains infectivity after undergoing routine sterilizing processes, the cause of bovine spongiform encephalopathy (BSE) outbreaks are suspected to be feeding cattle meat and bone meals (MBMs) contaminated with the prion. To assess the validity of prion inactivation by heat treatment in yellow grease, which is produced in the industrial manufacturing process of MBMs, we pooled, homogenized, and heat treated the spinal cords of BSE-infected cows under various experimental conditions. Results Prion inactivation was analyzed quantitatively in terms of the infectivity and PrP Sc of the treated samples. Following treatment at 140°C for 1 h, infectivity was reduced to 1/35 of that of the untreated samples. Treatment at 180°C for 3 h was required to reduce infectivity. However, PrP Sc was detected in all heat-treated samples by using the protein misfolding cyclic amplification (PMCA) technique, which amplifies PrP Sc in vitro . Quantitative analysis of the inactivation efficiency of BSE PrP Sc was possible with the introduction of the PMCA 50 , which is the dilution ratio of 10% homogenate needed to yield 50% positivity for PrP Sc in amplified samples. Conclusions Log PMCA 50 exhibited a strong linear correlation with the transmission rate in the bioassay; infectivity was no longer detected when the log PMCA 50 of the inoculated sample was reduced to 1.75. The quantitative PMCA assay may be useful for safety evaluation for recycling and effective utilization of MBMs as an organic resource.
Type of Medium:
Online Resource
ISSN:
1746-6148
DOI:
10.1186/1746-6148-9-134
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2013
detail.hit.zdb_id:
2191675-5
