Combinatorial treatment of brain samples from sheep with scrapie using sodium percarbonate, sodium dodecyl sulfate, and proteinase K increases survival time in inoculated susceptible sheep. (20th December 2022)

• Record Type: Journal Article
• Authors: Harm, Tyler A.; Smith, Jodi D.; Cassmann, Eric D.; Greenlee, Justin J.
• Is Part Of: Research in veterinary science. Volume 152(2022)
• Page Start: 497
• Page End: 503
• Publication Date: 2022-12-20
• Subjects: Decontamination -- Prion disease -- Scrapie -- Sheep -- Transmissible spongiform encephalopathy; Veterinary medicine -- Periodicals; Veterinary Medicine -- Periodicals; Médecine vétérinaire -- Périodiques; Médecine vétérinaire -- Recherche -- Périodiques; Diergeneeskunde; 636.089
• DOI: 10.1016/j.rvsc.2022.09.002
• Languages: English
• ISSNs: 0034-5288

Abstract

Abstract: The agent of scrapie is resistant to most chemical and physical methods of inactivation. Prions bind to soils, metals, and various materials and persist in the environment confounding the control of prion diseases. Most methods of prion inactivation require severe conditions such as prolong exposure to sodium hypochlorite or autoclaving, which may not be suitable for field conditions. We evaluated the efficacy of a combinatorial approach to inactivation of US scrapie strain x124 under the mild conditions of treating scrapie-affected brain homogenate with sodium percarbonate (SPC), sodium dodecyl sulfate (SDS), or in combination followed by proteinase K (PK) digestion at room temperature. Western blot analysis of treated brain homogenate demonstrates partial reduction in PrP Sc immunoreactivity. Genetically susceptible VRQ/ARQ Suffolk sheep were oronasally inoculated with 1 g of SPC ( n = 1), SDS ( n = 2), SDS + PK (n = 2), and SPC + SDS + PK ( n = 4) treated brain homogenate. Sheep were assessed daily for clinical signs, euthanized at the development of clinical disease, and tissues were assessed for accumulation of PrP Sc . Scrapie status in all sheep was determined by western blot, enzyme immunoassay, and immunohistochemistry. Mean incubation periods (IPs) for SPC (11.9 months, 0% survival), SDS (12.6 months, 0% survival), SDS + PK (14.0 months, 0% survival), and SPC + SDS + PK (12.5 months, 25% survival) were increased compared to positive control sheep ( n = 2, 10.7 months, 0% survival) by 1.2, 1.9, 3.3, and 1.8 months, respectively. Treatment did not influence PrP Sc accumulation and distribution at the clinical stage of disease. Differences in mean IPs and survival indicates partial but not complete reduction in scrapie infectivity. Highlights: The agent of scrapie is highly resistant to most chemical and physical methods of inactivation. Prion disease spread is difficult to control in the veterinary and animal agriculture communities. We evaluated the efficacy of a combinatorial approach to inactivation of US scrapie strain. Treatment did not appear to influence PrP Sc accumulation and distribution at clinical disease. Incubation period differences indicates only a partial reduction in scrapie infectivity.