The barriers to bluetongue virus infection, dissemination and transmission in the vector, Culicoides variipennis (Diptera: Ceratopogonidae)
The barriers to bluetongue virus infection, dissemination and transmission in the vector, Culicoides variipennis (Diptera: Ceratopogonidae)
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DOI：
10.1007/s007050050540
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发表时间：
1999-01-01
影响因子：
2.7
通讯作者：
Mellor, PS
中科院分区：
文献类型：
--
作者：
Fu, H;Leake, CJ;Mellor, PS
用免疫组织化学、病毒滴定和体外传播试验研究了蓝舌病毒(BTV)在库蚊媒介种间的传播。在口腔感染BTV后，从“传播能力”或“传播难治”的两个群体中选择了成年雌性变色隐翅虫。胸腔内注射BTV到血腔总是导致病毒在唾液中完全扩散感染和传播。然而，在摄入了传染性血粉后，两个群体中只有30%(大约)的蚊子持续感染。虽然来自“难治群”的经口感染的昆虫中没有一种能够传播病毒，但来自“有能力的”群(含有大于或等于10(3.0)TCID(50)的病毒/蚊子)的昆虫中，有12%的昆虫确实在它们的唾液中传播了BTV。在库蚊媒介物种中，BTV传播的最重要障碍似乎是控制持续感染初始建立的肠系膜感染屏障(MIB)、将病毒限制在肠道细胞内的肠系膜逃逸屏障(MEB)和阻止进入血腔的病毒感染次级靶器官的传播屏障(DB)。致病库蚊对BTV似乎既不存在唾液腺感染屏障(SGIB)，也不存在唾液腺逃逸屏障(SGEB)。
Transmission of bluetongue virus (BTV) by a vector species of Culicoides was studied using immunohistochemistry, virus titration and in vitro transmission tests. Adult female C. variipennis were used from two colonies that are either "transmission competent" or "transmission refractory" after oral infection with BTV. Intrathoracic (IT) injection of BTV into the haemocoel always resulted in a fully disseminated infection and transmission of virus in saliva. However, after ingestion of an infectious blood meal, only 30% (approximately) of midges from either colony became persistently infected. Although none of the orally infected insects from the "refractory" colony were able to transmit virus, 12% of those from the "competent" colony (containing greater than or equal to 10(3.0)TCID(50) of virus/midge) did transmit BTV in their saliva. The most important barriers to BTV transmission in Culicoides vector species appeared to be a mesenteron infection barrier (MIB), which controls initial establishment of persistent infection, a mesenteron escape barrier (MEB) which can restrict virus to gut cells and a dissemination barrier (DB) which can prevent virus which enters the haemocoel from infecting secondary target organs. Culicoides variipennis do not appear to present either a salivary gland infection barrier (SGIB), or a salivary gland escape barrier (SGEB) to BTV.