Evidence of scrapie transmission via milk.
Evidence of scrapie transmission via milk.
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DOI：
10.1186/1746-6148-4-14
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发表时间：
2008-04-08
影响因子：
2.6
通讯作者：
Simmons, Hugh A.
中科院分区：
文献类型：
--
作者：
Konold, Timm;Moore, S. Jo;Bellworthy, Susan J.;Simmons, Hugh A.
随着产羔时羊之间接触时间的延长和接触距离的增加，感染瘙痒病的风险也会增加。牛奶中尚未检测到痒病传染性，但在反刍动物的牛奶中发现了细胞朊病毒蛋白（疾病相关朊病毒蛋白 PrPd 的前体）。为了确定牛奶是否能够传播瘙痒病，18只带有与瘙痒病高度易感性相关的朊病毒蛋白基因型（VRQ/VRQ）的羔羊被喂食了12只受相同基因型的瘙痒病影响的母羊的牛奶，并用15只在无瘙痒病的母羊中饲养的VRQ/VRQ羊作为对照。分别在43日龄、44日龄和105日龄时因并发疾病而扑杀用患痒病母羊牛奶喂养的三只羔羊，前两只羔羊的远端回肠中检测到PrPd，而第三只羔羊的淋巴网状组织中未检测到PrPd。一只对照羔羊，饲养在单独的围栏中并在 38 天龄时被宰杀，其一系列组织中的 PrPd 也呈阴性。从其余 15 只 7 个月大（混合后 5 至 7 个月）的活羔羊中采集的直肠肛门粘膜相关淋巴组织样本，在痒病牛奶接受者中呈 PrPd 阳性，而当时在其余 14 只对照中未检测到 PrPd。随后从对照羔羊身上收集的样本显示，在与痒病奶接受者混合八个月后，五只羔羊中的两只体内出现了 PrPd 积累，这表明通过横向传播感染的早期阶段。相比之下，饲养在同一栋建筑中但未与瘙痒症牛奶接受者混在一起的对照羊的 PrPd 仍呈阴性。远端回肠和直肠粘膜中 PrPd 的存在表明瘙痒症通过牛奶（或初乳）从母羊传播给羔羊，尽管尚不清楚此类病例是否会继续发展为临床疾病。在约七个月龄时进行直肠粘膜检测显示，患瘙痒症牛奶的受者的高感染水平可能会因受者内部感染而增强或补充，因为这些羔羊在用受瘙痒症影响的母羊的牛奶喂养后混合在一起，而且我们还观察到从这些动物到无瘙痒症母羊断奶的羔羊的横向传播。
The risk of scrapie infection increases with increased duration and proximity of contact between sheep at lambing. Scrapie infectivity has not been detected in milk but cellular prion protein, the precursor of disease-associated prion protein PrPd, has been found in milk from ruminants. To determine whether milk is able to transmit scrapie, 18 lambs with a prion protein genotype associated with high susceptibility to scrapie (VRQ/VRQ) were fed milk from twelve scrapie-affected ewes of the same genotype, and 15 VRQ/VRQ sheep reared on scrapie-free dams served as controls. Three lambs fed milk from scrapie-affected ewes were culled due to intercurrent diseases at 43, 44 and 105 days of age respectively, and PrPd was detected in the distal ileum of the first two lambs, whilst PrPd was not found in lymphoreticular tissues in the third lamb. A control lamb, housed in a separate pen and culled at 38 days of age, was also negative for PrPd in a range of tissues. Samples of recto-anal mucosa associated lymphoid tissue collected from the remaining 15 live lambs at seven months of age (between five to seven months after mixing) were positive for PrPd in the scrapie milk recipients, whereas PrPd was not detected in the remaining 14 controls at that time. A subsequent sample collected from control lambs revealed PrPd accumulation in two of five lambs eight months after mixing with scrapie milk recipients suggestive of an early stage of infection via lateral transmission. By contrast, the control sheep housed in the same building but not mixed with the scrapie milk recipients were still negative for PrPd. The presence of PrPd in distal ileum and rectal mucosa indicates transmission of scrapie from ewe to lamb via milk (or colostrum) although it is not yet clear if such cases would go on to develop clinical disease. The high level of infection in scrapie-milk recipients revealed by rectal mucosal testing at approximately seven months of age may be enhanced or supplemented by intra-recipient infection as these lambs were mixed together after feeding with milk from scrapie-affected ewes and we also observed lateral transmission from these animals to lambs weaned from scrapie-free ewes.
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影响因子：
0.8
作者：
Espenes, A;Press, CM;Ulvund, MJ
通讯作者：
Ulvund, MJ
影响因子：
2.4
作者：
Ryder, S;Dexter, G;Tongue, S
通讯作者：
Tongue, S
影响因子：
5.4
作者：
Castilla, J;Brun, A;Torres, JM
通讯作者：
Torres, JM
影响因子：
3.8
作者：
Andréoletti, O;Berthon, P;Lantier, F
通讯作者：
Lantier, F
DOI：
10.1016/0007-1935(91)90029-m
发表时间：
1991-11-01
期刊：
BRITISH VETERINARY JOURNAL
影响因子：
--
作者：
FTHENAKIS, GC;ELMASANNAT, ETS;JONES, JET
通讯作者：
JONES, JET