Circulation of Nor98 Atypical Scrapie in Portuguese Sheep Confirmed by Transmission of Isolates into Transgenic Ovine ARQ-PrP Mice.
Int J Mol Sci
; 22(19)2021 Sep 28.
Article
em En
| MEDLINE
| ID: mdl-34638780
ABSTRACT
Portugal was among the first European countries to report cases of Atypical Scrapie (ASc), the dominant form of Transmissible Spongiform Encephalopathy (TSE) in Portuguese small ruminants. Although the diagnostic phenotypes observed in Portuguese ASc cases seem identical to those described for Nor98, unequivocal identification requires TSE strain-typing using murine bioassays. In this regard, we initiated characterization of ASc isolates from sheep either homozygous for the ARQ genotype or the classical scrapie-resistant ARR genotype. Isolates from such genotypes were transmitted to TgshpXI mice expressing ovine PrPARQ. Mean incubation periods were 414 ± 58 and 483 ± 107 days in mice inoculated with AL141RQ/AF141RQ and AL141RR/AL141RR sheep isolates, respectively. Both isolates produced lesion profiles similar to French ASc Nor98 'discordant cases', where vacuolation was observed in the hippocampus (G6), cerebral cortex at the thalamus (G8) level, cerebellar white matter (W1) and cerebral peduncles (W3). Immunohistochemical PrPSc deposition was observed in the hippocampus, cerebellar cortex, cerebellar white matter and cerebral peduncles in the form of aggregates and fine granules. These findings were consistent with previously reported cases of ASc Nor98 transmitted to transgenic TgshpXI mice, confirming that the ASc strain present in Portuguese sheep corresponds to ASc Nor98.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Scrapie
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Doenças Priônicas
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Proteínas Priônicas
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Genótipo
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article