Pathogenesis of Senecavirus A infection in finishing pigs
Pathogenesis of Senecavirus A infection in finishing pigs
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DOI：
10.1099/jgv.0.000631
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发表时间：
2016-12-01
影响因子：
3.8
通讯作者：
Diel, Diego G.
中科院分区：
文献类型：
--
作者：
Joshi, Lok R.;Fernandes, Maureen H. V.;Diel, Diego G.
Senecavirus A（SVA）是一种新出现的小核糖核酸病毒，与猪的水疱病和新生儿死亡有关。然而，SVA感染生物学和发病机制的许多方面仍然未知。本研究对育肥猪SVA的发病机理进行了研究。动物通过口鼻途径接种SVA菌株SD 15 -26，并监测与SVA感染相关的临床体征和病变。在血清中评估病毒血症，并通过实时逆转录酶定量PCR（RT-qPCR）和/或病毒分离监测口腔和鼻腔分泌物和粪便中的病毒脱落。此外，在急性感染期间和疾病恢复期后评估病毒载量和组织分布。在接种后第4天（pi）首次观察到以嗜睡和跛行为特征的临床体征，并持续约2-10天。在感染后第4天，在口鼻部和/或足上首次观察到水泡性病变，影响SVA感染动物的冠状带、狼爪、趾间间隙和脚跟/脚掌。在感染后第3 - 10天观察到短期病毒血症，而在感染后第1 - 28天在口腔和鼻腔分泌物和粪便中检测到病毒脱落。值得注意的是，对在感染后第38天收集的组织进行的RT-qPCR和原位杂交（ISH）揭示了所有SVA感染动物的扁桃体中存在SVA RNA。对SVA的血清学应答的特征在于早期中和抗体应答（感染后第5天），这与组织中病毒血症、病毒脱落和病毒载量水平降低一致。本研究为SVA在猪中的发病机制和感染动力学提供了重要的见解。
Senecavirus A (SVA) is an emerging picornavirus that has been associated with vesicular disease and neonatal mortality in swine. Many aspects of SVA infection biology and pathogenesis, however, remain unknown. Here the pathogenesis of SVA was investigated in finishing pigs. Animals were inoculated via the oronasal route with SVA strain SD15-26 and monitored for clinical signs and lesions associated with SVA infection. Viraemia was assessed in serum and virus shedding monitored in oral and nasal secretions and faeces by real-time reverse transcriptase quantitative PCR (RT-qPCR) and/or virus isolation. Additionally, viral load and tissue distribution were assessed during acute infection and following convalescence from disease. Clinical signs characterized by lethargy and lameness were first observed on day 4 post-inoculation (pi) and persisted for approximately 2-10 days. Vesicular lesions were first observed on day 4 pi on the snout and/or feet, affecting the coronary bands, dewclaws, interdigital space and heel/sole of SVA-infected animals. A short-term viraemia was observed between days 3 and 10 pi, whereas virus shedding was detected between days 1 and 28 pi in oral and nasal secretions and faeces. Notably, RT-qPCR and in situ hybridization (ISH) performed on tissues collected on day 38 pi revealed the presence of SVA RNA in the tonsils of all SVA-infected animals. Serological responses to SVA were characterized by early neutralizing antibody responses (day 5 pi), which coincided with decreased levels of viraemia, virus shedding and viral load in tissues. This study provides significant insights into the pathogenesis and infectious dynamics of SVA in swine.