| 摘要: |
| 对2015—2016年天津地区鲤鱼养殖场采集的发生鲤浮肿病毒（CEV）/锦鲤睡眠病（KSD）的鲤鱼样品，进行套式PCR检测和人工浸泡感染试验，并测定养成期鲤鱼感染率。实验观察研究发现，所采集样品均表现为体色发黑，头部上方颅骨软组织周围皱缩，眼球凹陷，鳃粘脏，黏液较多，常滞游于浅水区水面。套式PCR检测结果显示全部10个样品均出现特异性目的条带，为CEV阳性。目的产物测序后经NCBI BLAST，与已报道的CEV相关序列相似性介于85%—99%；系统发育树分析显示样品编号JY1856与JY1650位于同一分支，与已知CEV病毒株亲缘关系较近，而其余8个样品位于同一分支，与已知CEV病毒株亲缘关系较远。通过人工浸泡感染健康鲤鱼，半数致死时间为55d，累计死亡率为71.1%±3.2%，并从试验感染鱼组织中检测到CEV病毒DNA。养成期鲤鱼CEV携带率为77.5%。以上结果表明，天津地区养殖鲤鱼中存在CEV感染，揭示了我国鲤鱼养殖产业可能面临新的疫情，需引起养殖业的高度重视。 |
| 关键词: 鲤浮肿病毒(CEV)/锦鲤睡眠病(KSD) 套式PCR 系统发育树 人工感染试验 |
| DOI：10.11693/hyhz20171100281 |
| 分类号:S941;S965.1 |
| 基金项目:天津市水产局青年科技创新项目，J2018-07号；天津市教委科研计划项目，2017KJ186号。 |
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| PCR DETECTION AND ARTIFICIAL INFECTION TEST OF CARP EDEMA VIRUS (CEV) IN COMMON CARP CYPRINUS CARPIO IN CULTURED IN TIANJIN DISTRICT |
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LIU Qun1, HAN Jin-Gang1, WANG Jing1, ZHANG Dan2, HUO Wen-Hui1, CHEN Hao-Nan1, GENG Xu-Yun1, SUN Jin-Sheng1
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1.Tianjin Center for Control and Prevention of Aquatic Animal Infections Disease, Tianjin 300221, China;2.Tianjin Key Lab of Aqua-Ecology and Aquaculture, Department of Fisheries Science, Tianjin Agricultural University, Tianjin 300384, China
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| Abstract: |
| Ten carp samples suffering carp edema virus/koi sleepy disease (CEV/KSD) were collected from the carp farms in Tianjin district during 2015 and 2016. The samples were investigated by nested PCR, the artificial infection test was carried out in JY1650 collected in 2015, and the infection rate of carp in culture period was determined. All of the samples had the similar symptoms, including the skin of black body, the irregularly skull above the head, sunken eyes, the edge of gills with dirty, over-production mucus on the gills, and frequently stagnant in shallow water. All of the ten samples were detected as CEV positives by nested PCR. The sequences of the nested-PCR products showed 85% to 99% similarity with the reported CEV, after sequencing and BLAST on NCBI. The phylogenetic analysis of the target sequence showed that the samples of JY1650 and JY1856 formed a dependent brach on the phylogenetic tree with the other of 8 samples. So it had a closer relationship to CEV than those. Healthy koi was experimentally infected by immersion test using the homogenate of CEV infected gill, about 71.1%±3.2% of the infected animals was dead, median lethal time (LT50) was 55d, and viral DNA could be detected from these experimentally infected koi tissues. The infection rate of carp in culture period was 77.5%. The results indicate that the breeding carp in Tianjin district was infected with CEV. The carp aquaculture industry is facing a new epidemic situation, which should pay more attention. |
| Key words: CEV (carp edema virus)/KSD (koi sleepy disease) nested-PCR phylogenetic tree immersion test |
