Matsuyama Tomomasa, Atsumi Takashi, Kiryu Ikunari, Umeda Kousuke, Morimoto Natsuki
Japan Fisheries Research and Education Agency, Pathology Division, Aquaculture Research Department, Fisheries Technology Institute, Minami-Ise 516-0193, Mie, Japan.
Mie Prefecture Fisheries Research Institute, Shima 517-0404, Mie, Japan.
Pathogens. 2025 Jan 15;14(1):76. doi: 10.3390/pathogens14010076.
Pinctada birnavirus (PiBV) is the causative agent of summer atrophy in pearl oyster ( (Gould)). The disease, which induces mass mortality in juveniles less than 1 year old and abnormalities in adults, was first reported in Japan in 2019. Research on the disease has been hindered by the lack of cell lines capable of propagating PiBV. We established an ex vivo method for PiBV propagation using mantle tissue, the primary infection site of the virus. The method was used to investigate the proliferation characteristics of the virus at different culture temperatures and the sensitivity of the virus to UV radiation. The marginal zone of the mantle was found to be the most suitable for PiBV replication in terms of both viral yield and reproducibility. PiBV showed optimal propagation at an incubation temperature of 25 °C, with minimal to no increase at 15 °C or 32.5 °C. Using the tissue culture infectious dose 50 (TCID) measurement system developed in this study, we found that PiBV propagation was no longer detectable after UV irradiation at 6150 J/m or higher. The tissue fragment culture method developed in this study is expected to facilitate both ex vivo experiments and PiBV research.
珠母贝双RNA病毒（PiBV）是珍珠贝（古尔德）夏季萎缩病的病原体。该疾病在1岁以下幼体中引发大量死亡，在成体中导致异常，于2019年在日本首次报道。由于缺乏能够繁殖PiBV的细胞系，对该疾病的研究受到了阻碍。我们利用外套膜组织（病毒的主要感染部位）建立了一种PiBV体外繁殖方法。该方法用于研究病毒在不同培养温度下的增殖特性以及病毒对紫外线辐射的敏感性。就病毒产量和可重复性而言，发现外套膜边缘区最适合PiBV复制。PiBV在25℃的孵育温度下显示出最佳繁殖，在15℃或32.5℃时增殖极少或不增殖。使用本研究开发的组织培养感染剂量50（TCID）测量系统，我们发现紫外线照射剂量达到6150 J/m或更高时，PiBV的繁殖不再能被检测到。本研究开发的组织块培养方法有望促进体外实验和PiBV研究。
