Srisuvan Thinnarat, Noble Brenda L, Schofield Paul J, Lightner Donald V
Department of Livestock Development, 69/1 Phayathai Road, Bangkok 10400, Thailand.
Dis Aquat Organ. 2006 Jul 11;71(1):1-10. doi: 10.3354/dao071001.
Taura syndrome virus (TSV) infection in TSV-resistant (TSR) and TSV-susceptible (Kona) Litopenaeus vannamei (also called Penaeus vannamei) was investigated using histology, in situ hybridization (ISH), conventional reverse transcription polymerase chain reaction (RT-PCR) assays, and SYBR-Green real-time RT-PCR analysis. The shrimp were challenged by feeding with minced tissues of L. vannamei infected with 4 genotypic variants of TSV (Bz01, Th04, UsHi94, and Ve05). Survival probabilities of TSR shrimp were higher than those for Kona shrimp with all 4 variants. Th04, UsHi94, and Ve05 gave no Taura syndrome lesions with TSR shrimp. In contrast, TSR shrimp challenged with Bz01 and Kona shrimp with all 4 TSV variants exhibited severe necrosis of cuticular epithelial cells and lymphoid organ spheroids, indicative of acute and chronic phases of TSV infection, respectively. TSV was not detected by RT-PCR in TSR shrimp infected with Th04, UsHi94, and Ve05, or in Kona shrimp infected with Ve05 but was detected in TSR shrimp infected with Bz01 and in Kona shrimp infected with Bz01, Th04, and UsHi94. Real-time RT-PCR revealed that mean TSV copy numbers in TSR shrimp infected with Bz01, Th04, and UsHi94 were significantly (p < 0.0005) lower than those in Kona shrimp. In contrast, mean TSV copy numbers in TSR and Kona shrimp infected with Ve05 were not significantly different (p > 0.4). The results show that TSR L. vannamei are susceptible to infection but give high survival rates following challenge by all 4 variants of TSV.
利用组织学、原位杂交（ISH）、常规逆转录聚合酶链反应（RT-PCR）分析以及SYBR-绿实时RT-PCR分析，对耐桃拉综合征病毒（TSV）和易感TSV（科纳）的凡纳滨对虾（也称为南美白对虾）中的TSV感染情况进行了研究。通过投喂感染了4种TSV基因型变体（Bz01、Th04、UsHi94和Ve05）的凡纳滨对虾的碎组织来对虾进行攻毒。所有4种变体的耐TSV对虾的存活概率均高于科纳对虾。Th04、UsHi94和Ve05对耐TSV对虾未造成桃拉综合征病变。相比之下，用Bz01攻毒的耐TSV对虾以及用所有4种TSV变体攻毒的科纳对虾分别表现出表皮上皮细胞和淋巴器官球状体的严重坏死，分别指示TSV感染的急性期和慢性期。在感染Th04、UsHi94和Ve05的耐TSV对虾中，或在感染Ve05的科纳对虾中，RT-PCR未检测到TSV，但在感染Bz01的耐TSV对虾以及感染Bz01、Th04和UsHi94的科纳对虾中检测到了TSV。实时RT-PCR显示，感染Bz01、Th04和UsHi94的耐TSV对虾中的平均TSV拷贝数显著低于科纳对虾（p < 0.0005）。相比之下，感染Ve05的耐TSV对虾和科纳对虾中的平均TSV拷贝数没有显著差异（p > 0.4）。结果表明，耐TSV的凡纳滨对虾易受感染，但在受到所有4种TSV变体攻毒后具有较高的存活率。
