The early pathogenesis of foot-and-mouth disease in pigs infected by contact: a quantitative time-course study using TaqMan RT-PCR
The early pathogenesis of foot-and-mouth disease in pigs infected by contact: a quantitative time-course study using TaqMan RT-PCR
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DOI：
10.1099/0022-1317-82-4-747
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发表时间：
2001-04-01
影响因子：
3.8
通讯作者：
Donaldson, AI
中科院分区：
文献类型：
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作者：
Alexandersen, S;Oleksiewicz, MB;Donaldson, AI
口蹄疫（Foot-and-mouth disease，FMD）是一种危害偶蹄类动物的高度传染性病毒性疾病。本研究的目的是通过定量的时间过程研究来检测猪口蹄疫的早期发病机制。在实验条件下，受体猪通过与感染FMD的供体猪接触感染FMD，从感染后第1 ~ 4天每隔24 h随机抽取2头受体猪，处死后剖检。通过定量TaqMan RT-PCR方法和通过在原代牛甲状腺细胞上滴定FMD病毒来分析一系列组织。通过在细胞培养物中测定和从定量TaqMan数据计算的病毒滴度强烈相关（r > 0.9），从而确立了TaqMan计算的有效性。这些数据表明，病毒在肺部的复制仅对空气传播的病毒排泄起很小的作用。在这方面，咽、气管和鼻粘膜中的部位可能更重要。受体猪中最早的病毒感染和可能复制的部位似乎在咽部（软腭、扁桃体和咽底）。数据表明，口蹄疫病毒在猪体内复制迅速，大部分病毒扩增发生在皮肤中。提出了一个模型的感染进展，表明最初的传播从咽部区域，通过区域淋巴结，并通过血液上皮细胞，导致在几个周期的病毒扩增和传播。
Foot-and-mouth disease (FMD) is a highly contagious, economically important virus disease of cloven-hoofed animals. The objective of the present study was to examine the early pathogenesis of FMD in pigs by a quantitative time-course study. Under experimental conditions, recipient pigs were infected by contact with donor pigs affected by FMD, Every 24 h from day 1 to day 4 after exposure, two recipient pigs were selected randomly, killed and necropsied. A range of tissues were analysed by a quantitative TaqMan RT-PCR method and by titration of FMD virus on primary bovine thyroid cells. The titres of virus determined by assay in cell culture and calculated from the quantitative TaqMan data correlated strongly (r > 0.9), thereby establishing the validity of the TaqMan calculations. The data indicated that the replication of virus in the lungs contributes only in small part to airborne virus excretion. Sites in the pharynx, trachea and nasal mucosa are probably more important in that regard. The sites of earliest virus infection and possibly replication in recipient pigs appeared to be in the pharynx (soft palate, tonsil and floor of pharynx). The data indicated that FMD virus replication in pigs is rapid and that the majority of virus amplification occurs in the skin. A model for the progression of infection is proposed, indicating initial spread from the pharyngeal region, through regional lymph nodes and via the blood to epithelial cells, resulting in several cycles of virus amplification and spread.