鸭坦布苏病毒山东株的分离鉴定及其特性

Identification and characteristics of Shandong isolate of Tembusu virus

采用鸭胚尿囊腔接种、盲传的方法从山东某地区以瘫痪为主要特征的雏鸭脑组织中分离到1株病毒,并对分离病毒的生物学特性和理化特性进行了研究。结果显示,该病毒与GenBank上已发表的坦布苏病毒核苷酸同源性均高于98%,最高可达99.7%;病毒的ELD50为10-3.17/0.2mL,接种9日龄鸭胚,68h左右鸭胚死亡,胚体出血,肝脏肿大出血,尿囊膜增厚;病毒对胰蛋白酶、酸、氯仿和热敏感,0.5%的胰蛋白酶、pH<5和4.8%的氯仿条件下可将其灭活,56℃水浴20min或60℃水浴15 min可将其灭活,37℃处理24h毒力由10-3.17/0.2 mL下降至10-1.8/0.2mL;Mg2+不能提高病毒在50℃60min的稳定性;病毒未经酸碱处理不具有凝集鸡、鸭、鸽等红细胞的特性。接种7日龄雏鸭,48h后陆续发病,表现为病毒性脑炎;剖检变化为雏鸭脑水肿,脑部毛细血管充血、肝脏出血、腺胃出血、肺出血水肿,临床表现与自然发病相同。结果表明,该病毒分离株为坦布苏病毒。

A strain of virus was obtained from infected duckling characterized by paralysis. The study showed that the isolated virus is one strain of tembusu virus which was more closely related to TMUV （the highest similarity could be up to 99.7%） than other flaviviruses. The ELDs0 of the virus is 10^-3.17/0.2mL. The virus Could cause duck embryos died about 68 h with cutaneous hemorrhages and allantoic membrane thickening. The physical and chemical characteristics showed that the isolated virus was inactivated at 56℃ for 20 rain or 60℃ for 15 min and unstable at low pH（pH（5） ,it was sensitive to chloroform（at 4.8% concentration） and trypsin（at 0.5% concentration） and unstable at 50℃ for 1 h even with the protection of Mg2＋. The virus could not agglutinate the red blood cells of chicken,duck and pigeon. The virus is highly virulent when exprimentally inoculated intuo ducklings,the main pathological changes concluded brain edema, liver hemorrhage, the glandular stomach hemorrhage and lung hemorrhage ,its clinical manifestations is the same as natural cases. The study provided a theoretical basis for prevention of tembusu virus.