National Veterinary Institute, Technical University of Denmark (DTU-Vet), Division of Virology, Lindholm, DK-4771 Kalvehave, Denmark.
Vet Microbiol. 2013 Mar 23;162(2-4):330-337. doi: 10.1016/j.vetmic.2012.09.008. Epub 2012 Sep 12.
Foot-and-mouth disease virus (FMDV) RNA was measured using quantitative reverse transcription-PCR (qRT-PCR) assays in oral swab and probang samples collected from cattle and pigs during experimental infections with serotype O FMDV. During acute infection, FMDV RNA was measurable in oral swabs as well as in probang samples from both species. FMDV RNA could be detected in oral swabs and probang samples from a time point corresponding to the onset of viremia in directly inoculated animals, whereas animals which were infected through contact exposure had low levels of FMDV RNA in oral swabs before viral RNA could be measured in serum. Analysis of samples collected from cattle persistently infected with FMDV showed that it was not possible to detect FMDV RNA in oral swabs harvested beyond 10 days post infection (dpi), despite the presence of FMDV RNA in probang samples that had been collected as late as 35 dpi. An interesting feature of the persistent infection in the cattle was the apparent decline in the level of FMDV RNA in probang samples after the acute phase of infection, which was followed by a marked rise again (in all the carrier animals) by 28 dpi. Results from this study indicate that qRT-PCR analysis of oral swabs is a useful approach in order to achieve a time efficient and reliable initial diagnosis of acute FMD in cattle and pigs, whereas probang sampling is essential for the detection of cattle that are persistently infected "carriers" of FMDV.
口蹄疫病毒（FMDV）RNA 采用定量逆转录-PCR（qRT-PCR）检测方法，对实验感染 O 型 FMDV 的牛和猪的口腔拭子和探管样本进行了测量。在急性感染期间，在口腔拭子和两种动物的探管样本中均可检测到 FMDV RNA。FMDV RNA 可在与直接接种动物的病毒血症发作相对应的时间点，在口腔拭子和探管样本中检测到，而通过接触感染的动物在病毒 RNA 可在血清中测量之前，口腔拭子中 FMDV RNA 水平较低。对持续感染 FMDV 的牛采集的样本进行分析表明，尽管在采集到的探管样本中仍存在 FMDV RNA，但在感染后 10 天（dpi）之后，口腔拭子中无法检测到 FMDV RNA。牛持续感染的一个有趣特征是，在感染急性期之后，探管样本中 FMDV RNA 的水平明显下降，然后在 28 dpi 时再次明显上升（在所有的携带动物中）。本研究结果表明，qRT-PCR 分析口腔拭子是一种有用的方法，可用于快速有效地对牛和猪的急性 FMD 进行初始诊断，而探管采样对于检测持续感染的 FMDV“携带”牛是必不可少的。
