对虾白斑综合征病毒在螯虾动物模型的感染特性

Characterization of shrimp white spot syndrome virus(WSSV) infection in Cambarus proclarkii

应用克氏原螯虾作为动物模型研究对虾白斑综合征病毒 (WSSV)的感染增殖特性 ,涉及感染温度、感染途径、继发感染、半数致死量 (LD50 )、免疫保护及保存期等。结果显示 ,2 2～ 2 5℃时 ,接种WSSV的螯虾一般于 2～7d内死亡 ,温度升高对病毒增殖影响不显著 ,30～ 32℃时 ,平均死亡时间 2～ 6d ,温度降低对病毒增殖影响较显著 ,15～ 19℃时 ,接种螯虾平均 2～ 10d内死亡 ,8～ 10℃时 ,平均死亡时间 3～ 13d。感染途径分别用腹节肌肉、腹节皮下注射及口服 ,均能使螯虾感染发病 ,而浸泡方式不能使螯虾发病。细菌分离和细菌定量结果表明 ,寄生于螯虾心脏、肝胰腺内的阴沟肠杆菌在感染后期大量增殖 ,菌量分别是正常螯虾的 2 5和 30倍 ,形成继发感染。用螯虾测定WSSV的LD50 为 10 -6.5·mL-1种毒液。将病毒 5 6℃ ,30min灭活后免疫螯虾 ,不能使螯虾形成免疫保护。WSSV匀浆液 - 30℃冻存 1年后失活 ,而 - 30℃冻存于螯虾体内WSSV保存

Crawfishes (Cambarus proclarkii) as animal were infected with white spot syndrome virus (WSSV) for studying various infection characters, including temperature, transfer route, successive infection, median lethal dose (LD 50 ), immunity against virus and virus conservation etc. The results showed crawfishes usually died in 2-7d after infection at the temperature of 22-25℃, in 2-10d at 15-19℃,in 3-13d at 8-10℃ and 2-6d at 30-32℃.Below 5℃,the infected crawfishes could remain active for more than one month. By injecting and oral feeding, WSSV could infected crawfishes successfully and there was no significant difference between muscle injection and hypoderm injection. Soaking with WSSV failed to infect crawfishes. Bacteria examination in healthy and diseased crawfishes showed Enterobacter cloacae in the heart and hepatopancreas multiplied 25 and 30 times respectively, indicating that bacteria successive infection existed during the virus infection. The LD 50 was 10 -6.5 ·mL -1 WSSV. Crawfishes which were immunized with WSSV inactivated at 56℃ for 30min could not obtain immunity protection from.WSSV from homogenate stored at -30℃ for 1 year could not be recovered but from crawfishes stored at -30℃ for 1 year could be recovered successfully.