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Volume 31, Number 12—December 2025
Research
Silent Propagation of Classical Scrapie Prions in Homozygous K222 Transgenic Mice
Natalia Fernández-Borges1, Alba Marín-Moreno1, Juan Carlos Espinosa, Sara Canoyra, Olivier Andréoletti, and Juan María Torres
Table 2
Transmission of classical scrapie isolates to Q222-Tg501 homozygous mice and survival of mice in study of classical scrapie prions in homozygous K222 transgenic mice*
| Category | Isolate | 1st passage |
2nd passage |
|||
|---|---|---|---|---|---|---|
| Mean survival time + SD, d | No. diseased and PrPres-positive/no. inoculated | Mean survival time + SD, d | No. diseased and PrPres-positive/no. inoculated | |||
| I |
198/9 |
592 + 13 |
6/6 |
536 +46 |
5/5 |
|
| II | S2 | 228 + 15 | 6/6 | 233 + 4 | 6/6 | |
| CP060146 | 379 + 31 | 5/5 | ND | NA | ||
| CP060146/K222 goat |
415 + 40 |
6/6 |
ND |
NA |
||
| II + III | UKA2 | 245 + 36 | 5/5 | 252 + 8 | 6/6 | |
| F14 |
526 + 46 |
4/4 |
241 + 22 |
4/4 |
||
| IV | F10 | 449 + 19 | 5/5 | 372 + 14 | 6/6 | |
| F10/K222-Tg516 | 495 + 26 | 3/3 | ND | NA | ||
| C1 |
483 + 15 |
4/4 |
301 + 10 |
4/4 |
||
| Negative control | Healthy goat brain | >650 | 0/6† | >650 | 0/6† | |
*NA, not available; ND, not done; PrPres, proteinase K-resistant PrP. †Animals were found dead or euthanized at the end of their lifespan without showing clinical signs of classical scrapie.
1These first authors contributed equally to this article.
Page created: November 17, 2025
Page updated: December 23, 2025
Page reviewed: December 23, 2025
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