Lin Lisa, Chen Sammi, Russell Duncan S, Löhr Christiane V, Milston-Clements Ruth, Song Tiffany, Miller-Morgan Tim, Jin Ling
Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, United States.
Department of Microbiology, College of Science, Oregon State University, Corvallis, OR 97331, United States.
Virus Res. 2017 Aug 15;240:200-206. doi: 10.1016/j.virusres.2017.08.010. Epub 2017 Aug 30.
Koi herpesvirus (KHV) is a highly pathogenic virus of common carp and koi. KHV becomes latent in recovered koi or exposed koi without symptoms, and the latent infection can reactivate under stress conditions. KHV reactivation from latency often occurs when water temperature rapidly rises above 17°C. Dissolved O is lower at ≥17°C than at non-stress temperatures ≤15°C. To determine whether reduced dissolved O level has a role in KHV reactivation during temperature stress, KHV reactivation was investigated in KHV latently infected koi (KHV koi) under stress temperatures by maintaining dissolved O consistent with the O level at 15°C. There was no significant difference in the amount of reactivated virus between KHV koi maintained with and without O supplementation during temperature stress. Both handling and sampling were found to be stressful to koi and can contribute to KHV reactivation from latency. There was an increase in KHV genome within white blood cells (WBC) during KHV reactivation, which is about 3-4 fold higher than the amount of KHV genome detectable in WBC during the latency stage. At day 15 post-temperature stress (PTS), inflammation and necrosis were observed in multiple tissues, especially in the gills, eye, intestine, skin and kidney. KHV DNA was also detectable in multiple tissues on days 6, 9 and 15 PTS. Following day 3 PTS, the plasma cortisol levels were higher than that observed in koi before temperature stress, suggesting that KHV reactivation is associated with physiological stress in KHV koi.
锦鲤疱疹病毒（KHV）是鲤科鱼和锦鲤的一种高致病性病毒。KHV可在康复的锦鲤或无症状的暴露锦鲤中潜伏，且潜伏感染在应激条件下可重新激活。当水温迅速升至17°C以上时，KHV常从潜伏状态重新激活。17°C及以上时的溶解氧低于非应激温度（≤15°C）时的溶解氧。为了确定温度应激期间溶解氧水平降低是否在KHV重新激活中起作用，通过将溶解氧维持在与15°C时的氧水平一致，在应激温度下对潜伏感染KHV的锦鲤（KHV锦鲤）的KHV重新激活情况进行了研究。在温度应激期间，补充氧和未补充氧的KHV锦鲤重新激活的病毒量没有显著差异。发现处理和采样对锦鲤均有应激作用，且可促使KHV从潜伏状态重新激活。在KHV重新激活期间，白细胞（WBC）内KHV基因组增加，这比潜伏阶段WBC中可检测到的KHV基因组量高约3 - 4倍。温度应激后第15天（PTS），在多个组织中观察到炎症和坏死，尤其是鳃、眼、肠、皮肤和肾脏。在PTS第6、9和15天，多个组织中也可检测到KHV DNA。温度应激后第3天，血浆皮质醇水平高于温度应激前锦鲤中的水平，这表明KHV重新激活与KHV锦鲤的生理应激有关。
