安徽地区克氏原螯虾白斑综合征的诊断及朔源

Diagnosis of white spot syndrome virus in farm crawfish in Anhui province and its epidemiological source

摘要:

摘要:【目的】诊断安徽地区养殖的克氏原螯虾发生疫情的病原，追踪感染源，为疫病的防控提供依据。【方法】采集病料，参照OIE推荐的套式PCR 法检测白斑综合征病毒(WSSV)。将病螯虾鳃丝组织研磨后离心，取上清液接种健康克氏原螯虾。透射电镜观察病原特征。综合流行病源学及病原检测，分析养殖地区的可能感染源。【结果】发病螯虾感染了WSSV，动物实验可见和发病螯虾相同的临床症状，证实该病原引起养殖螯虾发病。电镜观察可见典型的白斑综合症病毒颗粒。流行病学调查显示，水产颗粒膨化饲料和冷冻饲料甲壳类检测阳性。【结论】该地区养殖的克氏原螯虾近年爆发的疫病病原为WSSV，推断地区性克氏原螯虾WSSV的感染并流行与污染的饲料有关。

Abstract:

Abstract:［Objective］ The aims of this study were to find out the pathogen causing high mortality of the crawfish population in Anhui over the past years．To provide the strategy for controlling the spread of the disease，an investigation was conducted to trace the origin of the pathogen．［Methods］Crawfish samples were tested by nested PCR，to diagnose the White Spot Syndrome Virus (WSSV)．Healthy crawfish were inoculated with the supernatant of tissue homogenates．The viral suspension was purified using sucrose density gradients． The gill samples infected with purified virus were then subject to the transmission electron microscopy (TEM)．The possible sources，including pond water，feedstuff，crabs，water plants，were investigated．［Results］ Crawfish samples and commercial feeds exhibited all positive for WSSV． Challenge model on healthy crawfish recovered similar symptoms as the naturally infected ones on 7 to 9 days after inoculation． The viral particles were observed under TEM．［Conclusion］ Our findings indicated that WSSV was the causative agent that led to high mortality in the crawfish population in this area．These results demonstrated that the exotic viruses are derived from the regions where the frozen feeds were contaminated with WSSV-infected shell debris．