Kim Kyung-Ho, Kang Gyoungsik, Woo Won-Sik, Sohn Min-Young, Son Ha-Jeong, Kwon Mun-Gyeong, Kim Jae-Ok, Park Chan-Il
Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea.
Aquatic Disease Control Division, National Fishery Products Quality Management Service, 216, Gijanghaean-ro, Gijang, Busan 46083, Republic of Korea.
Animals (Basel). 2023 Mar 30;13(7):1210. doi: 10.3390/ani13071210.
Red sea bream iridovirus (RSIV) causes significant economic losses in aquaculture. Here, we analyzed the pathogenicity, viral shedding, and transmission dynamics of RSIV in rock bream () by employing immersion infection and cohabitation challenge models. Rock bream challenged by immersion exposure exhibited 100% mortality within 35 days post RSIV exposure, indicating that the viral shedding in seawater peaked after mortality. At 25 °C, a positive correlation between the viral loads within infected rock bream and virus shedding into the seawater was observed. Specific RSIV lesions were observed in the spleen and kidney of the infected rock bream, and the viral load in the spleen had the highest correlation with the histopathological grade. A cohabitation challenge mimicking the natural transmission conditions was performed to assess the virus transmission and determine the pathogenicity and viral load. The RSIV-infected rock breams (donors) were cohabited with uninfected rock bream, red sea bream (), and flathead grey mullet () (recipients) at both 25 °C and 15 °C. In the cohabitation challenge group maintained at 15 °C, no mortality was observed across all experimental groups. However, RSIV was detected in both seawater and the recipient fish. Our results provide preliminary data for further epidemiological analyses and aid in the development of preventive measures and management of RSIVD in aquaculture.
真鲷虹彩病毒（RSIV）给水产养殖业造成了重大经济损失。在此，我们通过采用浸泡感染和同居挑战模型，分析了RSIV在条石鲷（）中的致病性、病毒排放及传播动态。经浸泡暴露挑战的条石鲷在RSIV暴露后35天内死亡率达100%，这表明海水里的病毒排放在死亡后达到峰值。在25℃时，观察到受感染条石鲷体内的病毒载量与排入海水中的病毒之间呈正相关。在受感染条石鲷的脾脏和肾脏中观察到了特定的RSIV损伤，且脾脏中的病毒载量与组织病理学分级的相关性最高。进行了模拟自然传播条件的同居挑战，以评估病毒传播并确定致病性和病毒载量。将受RSIV感染的条石鲷（供体）与未受感染的条石鲷、真鲷（）和平头鲻（）（受体）在25℃和15℃下同居。在15℃下维持的同居挑战组中，所有实验组均未观察到死亡情况。然而，在海水和受体鱼中均检测到了RSIV。我们的结果为进一步的流行病学分析提供了初步数据，并有助于制定水产养殖中RSIVD的预防措施和管理方法。
