为研究鲤浮肿病毒的感染方式及在锦鲤各组织器官中的动态分布, 在水温20～22℃, 溶解氧7～8mg/L试验条件下, 采用注射、浸泡、划伤后浸泡3种方式人工感染锦鲤, 观察了试验鱼的发病和死亡情况;检测了鲤浮肿病毒在感染鱼体内各组织器官中的存在情况, 探讨了主要被感染组织的病理变化.试验结果显示, 采用注射、浸泡、划伤后浸泡3种方式均可导致健康锦鲤感染该病毒, 病鱼出现昏睡、烂鳃、凹眼等症状, 累积死亡率35％～88％.锦鲤感染该病毒后至少有3d的潜伏期, 随后病毒在鳃组织中大量增殖, 至7d达到高峰, 病毒量314.8个/ng, 之后病毒量开始逐渐下降, 至12d在鳃组织中检测不出病毒.鲤浮肿病毒在肾、肝、脑、肌肉和脾中存在的时间较短且病毒量较低, 在血液和肠道中未检出.结合鳃组织病理切片可知, 鳃为该病毒感染的主要靶器官.本研究结果为鲤浮肿病的诊断和防控提供了一定的科学依据.%To study the artificial infection of Carp edema virus (CEV) and its dynamic distribution in different organs, artificial infecting tests were carried out by injection, by bath with and without scarifiction on skin using filtrated suspension of gills and kidney homogenates obtained from sick fish.The experimental water conditions were kept at temperature of 20—22℃and at dissolved oxygen level of 7—8mg/L.Morbidity and mortality were observed and CEV were examined in gill, hepatopancreas, kidney, spleen, brain, blood, intestine and muscle by real-time PCR.The histopathological changes in the gills of infected koi Cyprinus carpio koi were assayed also.The results showed that CEV infected healthy koi by injection or by bath, especially by bath with scarification.And the sick koi showed typical clinical signs of CEVD including lethargy, rot gills and enophthalmos, with cumulative mortality of 35％—88％.In addition, CEV had a latent period of 3das post-infection at least, proliferated in gill tissue subsequently and reached its peak at 7dpost-infection as the virus loaded about 314.8copies/ng tissues.Then virus loads began to decline gradually, and were not be detected at 12dpost-infection.By contrast, CEV showed shorter multiplication time and lower virus loads in kidney, hepatopancreas, brain, muscle and spleen, without in blood and intestine.So combined with the histopathological observation, it was speculated that gill was one of the main target organs for CEV.The findings will provide a scientific basis for diagnosis, prevention and control of CEVD.
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