Department of Food Safety & Infection Biology, Norwegian School of Veterinary Science, Postboks 8146 Dep, N-0033 OSLO Norwegian, Norway.
Vet Res. 2012 Apr 9;43(1):27. doi: 10.1186/1297-9716-43-27.
Aquaculture is the fastest growing food production sector in the world. However, the increased production has been accompanied by the emergence of infectious diseases. Heart and skeletal muscle inflammation (HSMI) is one example of an emerging disease in farmed Atlantic salmon (Salmo salar L). Since the first recognition as a disease entity in 1999 it has become a widespread and economically important disease in Norway. The disease was recently found to be associated with infection with a novel reovirus, piscine reovirus (PRV). The load of PRV, examined by RT-qPCR, correlated with severity of HSMI in naturally and experimentally infected salmon. The disease is characterized by epi-, endo- and myocarditis, myocardial necrosis, myositis and necrosis of the red skeletal muscle. The aim of this study was to investigate the presence of PRV antigens in heart tissue of Atlantic salmon and monitor the virus distribution in the heart during the disease development. This included target cell specificity, viral load and tissue location during an HSMI outbreak. Rabbit polyclonal antisera were raised against putative PRV capsid proteins μ1C and σ1 and used in immunohistochemical analysis of archived salmon heart tissue from an experimental infection. The results are consistent with the histopathological changes of HSMI and showed a sequential staining pattern with PRV antigens initially present in leukocyte-like cells and subsequently in cardiomyocytes in the heart ventricle. Our results confirm the association between PRV and HSMI, and strengthen the hypothesis of PRV being the causative agent of HSMI. Immunohistochemical detection of PRV antigens will be beneficial for the understanding of the pathogenesis of HSMI as well as for diagnostic purposes.
水产养殖是世界上增长最快的食品生产部门。然而，产量的增加伴随着传染病的出现。心脏和骨骼肌炎症（HSMI）是养殖大西洋鲑鱼（Salmo salar L）中出现的一种新兴疾病的例子。自 1999 年首次被确认为一种疾病实体以来，它已成为挪威一种广泛存在且具有重要经济意义的疾病。最近发现，这种疾病与一种新型呼肠孤病毒，即鱼类呼肠孤病毒（PRV）的感染有关。通过 RT-qPCR 检查的 PRV 负荷与自然和实验感染鲑鱼的 HSMI 严重程度相关。该疾病的特征为上皮、内皮和心肌炎、心肌坏死、肌炎和红骨骼肌坏死。本研究的目的是调查大西洋鲑鱼心脏组织中 PRV 抗原的存在，并监测在疾病发展过程中心脏中病毒的分布。这包括靶细胞特异性、病毒载量和 HSMI 爆发期间的组织位置。针对 PRV 衣壳蛋白 μ1C 和 σ1 制备了兔多克隆抗血清，并用于对来自实验感染的存档鲑鱼心脏组织进行免疫组织化学分析。结果与 HSMI 的组织病理学变化一致，并显示出 PRV 抗原的顺序染色模式，最初存在于白细胞样细胞中，随后存在于心室的心肌细胞中。我们的结果证实了 PRV 与 HSMI 之间的关联，并加强了 PRV 是 HSMI 致病因子的假设。PRV 抗原的免疫组织化学检测将有助于了解 HSMI 的发病机制以及诊断目的。
