致麻鸭产蛋下降的副粘病毒的分离和鉴定

Isolation and Identification of Paramyxovirus Causing duck Egg Drop

从浙江省某麻鸭养殖基地产蛋锐减的病鸭生殖器官分离到1株致产蛋下降、不致鸭死亡的病毒株(YH99V)。该病毒易感蛋鸭,经SPF鸡胚传至第9代时致病性突然增强,第11代出现对鸡红细胞的血凝特性,通常在42～80h致死SPF鸡胚,EF15EID50为10-4.8。经磷钨酸负染电镜观察,YH99V粒子呈现圆形、杆状形、葫芦状形等多形态,直径70～400nm不等,病毒外表有囊膜,囊膜外层有排列整齐的纤突。病毒粒子和包涵体位于细胞浆内。病毒抵抗力由弱到强依次为0.2%甲醛、24h→56℃、45min→紫外线、1h→乙醚≈氯仿≈37℃、16h→pH9→pH5→1%Try。对人眼结膜易感,鸭眼结膜不易感。接种传代细胞BHK-21、IBRS-2均能引起细胞病变。YH99V株与同样引起鸭产蛋下降的AIV、鸭源EDSV无抗原相关性,而能被禽副粘病毒型阳性血清中和。根据试验结果,初步将YH99V判定为鸭副粘病毒。

One strain virus(YH_~99 V) was isolated from the duck reproductive organ in a laying duck farm of zhejiang province,The isolate attacked the laying duck easily,generally resulted to egg drop,but didn′t cause duck to die.The pathogenesis of strain YH_~99 V was strengthened suddenly during the 9~th generation of specific pathogen free(SPF) chicken embryo,and didn′t present hemagglutination to chicken′s erythocyte until the 11~th generation.It took 42-80 h for chicken embryo′s dead,and EF_~15 ,EID_~50 was 10^-4.8 .YH_~99 V particles appeared the numerous irregulated-shapes of circle,bacilliform or cucurbit-shape and so on,diameter was about 70-400 nm by electron-microscope detection using phosphotungstic acid negative dye.There was envelope outside the virus particle and tidily-arranged peplomeres outside the envelope.The virus particles and inclusion-bodies lay in cytoplasm,Resistance of the virus gradually strengthened as following:0.2% methanal 24 h→56℃,45 min→ultraviolet,1 h→ethyl ether≈chloroform≈37℃,16 h→pH9→pH5→1% trypsin.The isolate was able to propagated in cells of BHK-21 and IBRS-2 and caused to cytopathogenic effect(CPE).It infected conjunctiva of human easily,but not to that of duck.It was no relevant antigen to EDSV came from duck and AIV(H5,H7 and H9) which caused duck egg drop,but was neutralized by positive sera of avian paramyxovirus type 1.These results suggested that the isolated YH_~99 V was duck paramyxovirus.