National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai 201306, China.
National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
Viruses. 2021 Sep 3;13(9):1761. doi: 10.3390/v13091761.
Cyprinid herpesvirus 2 (CyHV-2), a member of the Alloherpesviridae family belonging to the genus , is a fatal contagious aquatic pathogen that affects goldfish () and crucian carp (). Although crucian carp and goldfish belong to the genus , it is unclear whether they are susceptible to the same CyHV-2 isolate. In addition, the origin of the crucian carp-derived CyHV-2 virus isolate remains unclear. CyHV-2 SH01 was isolated during herpesviral hematopoietic necrosis disease (HVHN) outbreaks in crucian carp at a local fish farm near Shanghai. CyHV-2 SH01 was confirmed by PCR and Western blot analysis of kidney, spleen, muscle, and blood tissue from the diseased crucian carp. Moreover, histopathological and ultra-pathological analyses revealed pathological changes characteristic of CyHV-2 SH01 infection in the tissues of the diseased crucian carp. In the present study, goldfish and crucian carp were challenged with CyHV-2 SH01 to elucidate viral virulence. We found that CyHV-2 SH01 could cause rapid and fatal disease progression in goldfish and crucian carp 24 h post-injection at 28 °C. Experimental infection of goldfish by injection indicated that the average virus titer in the kidney of the goldfish was 10 to 10 copies/mg. In addition, tissues exhibited the most prominent histopathological changes (cellular wrinkling and shrinkage, cytoplasmic vacuolation, fusion of the gill lamellae, and hepatic congestion) in CyHV-2 SH01-infected goldfish and crucian carp. Thus, crucian carp and goldfish showed a high sensitivity, with typical symptoms, to HVHN disease caused by CyHV-2 SH01.
锦鲤疱疹病毒 2 型（CyHV-2）属于疱疹病毒科的 Alloherpesviridae 家族，是一种致命的传染性水生病原体，可感染金鱼（Carassius auratus）和鲫鱼（Carassius auratus）。尽管鲫鱼和金鱼属于同一个属，但它们是否对相同的 CyHV-2 分离株敏感尚不清楚。此外，鲫鱼来源的 CyHV-2 病毒分离株的起源也不清楚。CyHV-2 SH01 是在上海附近的一个当地养鱼场爆发的鲫鱼疱疹病毒性造血坏死病（HVHN）期间从鲫鱼中分离出来的。通过对患病鲫鱼的肾脏、脾脏、肌肉和血液组织进行 PCR 和 Western blot 分析，证实了 CyHV-2 SH01 的存在。此外，组织学和超微病理学分析显示，患病鲫鱼组织中存在 CyHV-2 SH01 感染的特征性病理变化。在本研究中，用 CyHV-2 SH01 对金鱼和鲫鱼进行了攻毒试验，以阐明病毒的毒力。我们发现，CyHV-2 SH01 在 28°C 24 小时内可导致金鱼和鲫鱼迅速致命。金鱼的注射实验感染表明，金鱼肾脏中的平均病毒滴度为 10 到 10 拷贝/mg。此外，组织学观察显示，在感染 CyHV-2 SH01 的金鱼和鲫鱼中，组织表现出最显著的组织病理学变化（细胞皱缩和收缩、细胞质空泡化、鳃片融合和肝淤血）。因此，鲫鱼和金鱼对由 CyHV-2 SH01 引起的 HVHN 疾病表现出高度敏感性，具有典型症状。
