Goodwin Andrew E, Merry Gwenn E
Aquaculture/Fisheries Center University of Arkansas at Pine Bluff 1200 North University Drive, Pine Bluff, Arkansas 71601, USA.
J Aquat Anim Health. 2011 Jun;23(2):85-91. doi: 10.1080/08997659.2011.574086.
The emergence of the viral hemorrhagic septicemia virus (VHSV) genotype IVb (VHSV-IVb) in the Great Lakes of North America has led to concern that the virus might spread to natural fisheries and aquaculture in the southern USA. We exposed bluegills Lepomis macrochirus to VHSV-IVb by intraperitoneal injection at six temperatures from 10 degrees C to 30 degrees C and followed the disease course by quantitative real-time reverse transcriptase polymerase chain reaction (qrt-RT-PCR). Mortality of injected fish was 90% at 10 degrees C, 35% at 14 degrees C, and 10% at 18 degrees C; no mortality attributable to VHSV was observed at temperatures of 22-30 degrees C. In survivors tested at 21 d postchallenge, viral copies and prevalence determined by qrt-RT-PCR were inversely related to temperature, and VHSV-IVb could not be detected in fish held at temperatures above 22 degrees C. Similar results were obtained for bluegills that were exposed by cohabitation with the intraperitoneally injected fish. Acclimation of the fish to 12 degrees C after 21 d at higher temperatures did not appear to cause a re-emergence of the virus. Based on our findings, the temperature range of VHSV-IVb appears to be the same as published values for VHSV genotype I, which has an optimum of 9-12 degrees C and an upper limit of 18-20 degrees C.
北美五大湖出现的病毒性出血性败血症病毒（VHSV）IVb基因型（VHSV-IVb）引发了人们对该病毒可能传播至美国南部天然渔场和水产养殖区的担忧。我们将蓝鳃太阳鱼（Lepomis macrochirus）在10℃至30℃的六个温度下通过腹腔注射暴露于VHSV-IVb，并通过定量实时逆转录聚合酶链反应（qrt-RT-PCR）跟踪疾病进程。注射后的鱼在10℃时死亡率为90%，14℃时为35%，18℃时为10%；在22 - 30℃的温度下未观察到由VHSV引起的死亡。在攻毒后21天对存活鱼进行检测时，qrt-RT-PCR测定的病毒拷贝数和流行率与温度呈负相关，在温度高于22℃饲养的鱼中未检测到VHSV-IVb。与腹腔注射鱼同居暴露的蓝鳃太阳鱼也得到了类似结果。在较高温度下饲养21天后将鱼适应至12℃似乎并未导致病毒再次出现。基于我们的研究结果，VHSV-IVb的温度范围似乎与已公布的VHSV I型的值相同，其最适温度为9 - 12℃，上限为18 - 20℃。
