Virological, serological and histopathological evaluation of fish strain susceptibility to experimental infection with salmonid alphavirus
Virological, serological and histopathological evaluation of fish strain susceptibility to experimental infection with salmonid alphavirus
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DOI：
10.3354/dao072125
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发表时间：
2006-10-17
影响因子：
1.4
通讯作者：
Todd, D.
中科院分区：
文献类型：
--
作者：
McLoughlin, M. F.;Graham, D. A.;Todd, D.
养殖大西洋鲑鱼 Salmo salar L. 的胰腺病 (PD) 是由一种称为鲑鱼胰腺病病毒 (SPDV) 的甲病毒引起的，可能会造成严重的经济后果。 2003年在爱尔兰进行的一项流行病学调查表明，根据临床疾病和死亡率水平衡量，各个养殖场内不同品种的养殖大西洋鲑鱼对SPDV感染的易感性存在显着差异。这项初步研究的目的是通过比较实验感染 SPDV 的 3 种商业大西洋鲑鱼品系（A、B 和 C）的病变发展、病毒血症和血清学反应来调查这一现场观察。感染后第 21 天 (pi) 检测到胰腺病变严重程度存在高度显着差异 (p < 0.01)，其中 B 组受影响更严重。感染后第 21 天和第 35 天，心脏和骨骼肌病变的患病率和严重程度也存在显着差异，B 组结果再次显着高于 A 组和 C 组（p < 0.05）。病毒血症和特异性 SPDV 抗体的存在之间没有重叠。所有组中的一些鱼都没有病毒血症、病变或血清转化的证据。在每个时间点的病毒血症鱼的百分比方面，攻击组之间没有观察到显着差异。未测定病毒载量。在感染后第 28 天和第 35 天发现每个攻击组中抗体阳性鱼的数量存在差异 (p < 0.1)。第 28 天检测到血清阳性鱼的几何平均滴度存在高度显着差异 (p < 0.01)。这些结果是使用攻击模型获得的，证实商业养殖大西洋鲑鱼对实验性 SPDV 感染的易感性存在菌株差异。
Pancreas disease (PD) of farmed Atlantic salmon Salmo salar L., which is caused by an alphavirus known as salmon pancreas disease virus (SPDV), can have serious economic consequences. An epidemiological survey carried out in Ireland in 2003 indicated that within individual farms there were significant differences in the susceptibility of different strains of farmed Atlantic salmon to infection with SPDV, as measured by levels of clinical disease and mortality. The aim of this preliminary study was to investigate this field observation by comparing lesion development, viraemia and serological responses of 3 commercial strains of Atlantic salmon (A, B and C) experimentally infected with SPDV. Highly significant differences in the severity of lesions in the pancreas at Day 21 post-infection (pi) were detected (p < 0.01), with Group B being more severely affected. There were also significant differences in the prevalence and severity of lesions in heart and skeletal muscle at Day 21 and 35 pi respectively, with Group B results again significantly higher than those from both Groups A and C (p < 0.05). There was no overlap between viraemia and the presence of specific SPDV antibody. Some fish in all groups had no viraemia, lesions or evidence of seroconversion. There were no significant differences seen between the challenged groups in relation to the percentage of viraemic fish at each time point. Viral loads were not determined. Differences between the number of antibody-positive fish in each challenge group were found at Days 28 and 35 pi (p < 0.1). Highly significant differences (p < 0.01) in the geometric mean titres of seropositive fish were detected at Day 28. These results, obtained using a challenge model, confirm that there are strain differences in the susceptibility to experimental SPDV infection in commercial farmed Atlantic salmon.