对虾白斑综合征病毒射阳株的分离及其在螯虾体内的动态分布

Isolation and dynamic distribution of white spot syndrome virus Sheyang strain in crawfishes

从江苏射阳某对虾养殖场采集患白斑综合征的病死对虾 ,以对虾组织匀浆液接种克氏原螯虾并传至 2代 ,结果螯虾全部发病死亡。用斑点杂交和单抗ELISA检测对虾和 2代螯虾 ,均为白斑综合征病毒 (WSSV)阳性 ,将此WSSV命名为射阳株。进一步用斑点杂交和单抗ELISA检测射阳株在肌注和口服感染螯虾体内的动态分布 ,并与青岛株的动态分布相比较。口服和肌注螯虾在感染后 12h ,病毒首先在血淋巴中检出 ,然后减少 ,36h后又明显检出 ,并增加至高峰然后减少 ;肠上皮、心脏、肌肉中的病毒在口服和肌注感染后 36h同时出现并呈总体递增分布 ;此外 ,病毒在胃上皮、真皮和结缔组织中也有不同程度的分布。感染死亡螯虾各主要组织器官均可检出病毒 ;电镜观察死亡螯虾鳃、心脏、肝胰腺、真皮、卵巢等器官的超薄切片 ,均可见到典型的病毒粒子 ,显示死亡螯虾内病毒已形成周身感染。WSSV射阳株与青岛株在螯虾的动态分布具有相似性。

Died shrimps collected from a shrimp farm in 1999 in Sheyang,Jiangsu Province,were homogenized and taken to inoculate crawfishes.The infected crawfishes all died within 4?8 days and the crawfishes inoculated with tissue supernatant of the died crawfishes also died within 6?8 days.The tissue samples of died shrimps and crawfishes were all positive of white spot syndrome virns(WSSV) in MAb mediated ELISA and Dot blot,so the isolated virus was designated as WSSV Sheyang strain.The dynamic distribution of the WSSV Sheyang strain in crawfishes was studied and compared to that of WSSV Qingdao strain.WSSV was first detected in heamolymph at 12 h p i in both oral infection and injection group and decreased.At 36 h p i ,WSSV was obviously detected once again,increasing to maximum amount and then declining.WSSV in intestine epithelium,heart and muscle of both groups was detected at 36 h p i and increased generally.In addition,WSSV in stomach epithelium,hypoderm,connective tissue of oral infection group and stomach epithelium,hypoderm of injection group could be also detected.In died shrimp,WSSV could be detected in all the examined tissues by Dot blot,ELISA and EM,suggesting systemic infection had occurred.It suggested the dynamic distribution of the WSSV Sheyang strain in crawfishes was similar to that of Qingdao strain.