Viral hemorrhagic septicemia virus (VHSV) is an important viral pathogen in the culture of Olive Flounder Paralichthys olivaceus. Based on cumulative mortality, the virulence of VHSV was found to be highly different depending on challenge routes and exposure doses (using tissue culture infectious dose with 50% endpoint [TCID50]). Olive Flounder were injected with VHSV at 102.5 , 104.5 , 106.5 , and 108.5 TCID50/100 μL/fish. A second group of fish was immersed at 103.5 , 105.5 , and 107.5 TCID50/mL at 10°C for 1 h in this study. The cumulative mortality was observed at 15 d postinfection. Immersion challenge at 103.5 TCID50/mL caused no mortality, while intramuscular injection challenge resulted in high levels of mortality with all VHSV exposure doses. Overall, Olive Flounder was susceptible to VHSV, with cumulative mortality of 90% or 100% in fish intramuscularly injected with high or low doses of VHSV. The cumulative mortality was 40% and 70% at 105.5 and 107.5 TCID50/mL, respectively, in the immersion challenge group. The VHSV titration and copy numbers were estimated by TCID50 and quantitative reverse transcription PCR methods. From dead Olive Flounder, VHSV titration was consistently detected in all tested organs, ranging from 105 to 109 TCID50/mL. The VHSV titration was under the detection limit from surviving Olive Flounder, but the VHSV N gene was detected.

中文翻译：

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肌肉注射和浸泡激发橄榄比目鱼死亡器官和存活器官之间病毒性出血性败血症病毒载量的差异

病毒性出血性败血症病毒 (VHSV) 是橄榄比目鱼 Paralichthys olivaceus 培养中的重要病毒病原体。根据累积死亡率，发现 VHSV 的毒力因攻击途径和暴露剂量而异（使用具有 50% 终点的组织培养感染剂量 [TCID50]）。橄榄比目鱼注射了 102.5、104.5、106.5 和 108.5 TCID50/100 μL/鱼的 VHSV。在本研究中，第二组鱼在 103.5、105.5 和 107.5 TCID50/mL 的温度下在 10°C 下浸泡 1 小时。在感染后 15 天观察到累积死亡率。103.5 TCID50/mL 的浸没攻击不会导致死亡，而肌肉注射攻击导致所有 VHSV 暴露剂量的高死亡率。总体而言，橄榄比目鱼容易感染 VHSV，肌肉注射高剂量或低剂量 VHSV 的鱼的累积死亡率为 90% 或 100%。在 105.5 和 107.5 TCID50/mL 时，浸泡攻击组的累积死亡率分别为 40% 和 70%。VHSV 滴定和拷贝数通过 TCID50 和定量逆转录 PCR 方法估计。从死亡的橄榄比目鱼身上，在所有测试器官中始终检测到 VHSV 滴定，范围从 105 到 109 TCID50/mL。VHSV 滴定低于幸存的橄榄比目鱼的检测限，但检测到 VHSV N 基因。VHSV 滴定和拷贝数通过 TCID50 和定量逆转录 PCR 方法估计。从死亡的橄榄比目鱼身上，在所有测试器官中始终检测到 VHSV 滴定，范围从 105 到 109 TCID50/mL。VHSV 滴定低于幸存的橄榄比目鱼的检测限，但检测到 VHSV N 基因。VHSV 滴定和拷贝数通过 TCID50 和定量逆转录 PCR 方法估计。从死亡的橄榄比目鱼身上，在所有测试器官中始终检测到 VHSV 滴定，范围从 105 到 109 TCID50/mL。VHSV 滴定低于幸存的橄榄比目鱼的检测限，但检测到 VHSV N 基因。