企鹅新城疫强毒人工感染北京雏鸭的研究

The Trial of Pekin Ducklings Experimentally Infected with Virulent Newcastle Disease Virus Isolated from Penguin

以分离鉴定的企鹅新城疫强毒 (PNDV)经静脉注射、肌肉注射和滴鼻点眼等途径分别人工感染 7日龄和 14日龄的北京雏鸭 ,结果只有静脉注射组雏鸭发病死亡 ,其致死率分别为 10 0 %和 5 0 % ,且自死亡雏鸭脑组织中均可重新分离到PNDV。而肌肉注射组雏鸭和滴鼻点眼组雏鸭于接毒后 14天内均未表现任何异常 ,但可诱导产生较高效价的特异性抗体 ,然而抗体效价在短时间内迅速下降 ,且自其脑和脾脏中均未分离到PNDV。试验结果表明北京鸭对PNDV的易感性不强 ,即使经静脉注射其致死率也随着日龄的增大而降低 ;而经肌肉注射或滴鼻点眼途径均未能使北京雏鸭发病 。

day_old and 14_day_old Pekin ducklings were experimentally infected with virulent Newcastle disease virus isolated from penguin(PNDV) by intravenous injection, intramuscular injection or nose/eye_dropping respectively.Only ducklings inoculated by intravenous injection showed obvious nervous sign and died, the mortality of the 7_day_old ducklings was 100%,while that of the 14_day_old ducklings was only 50%. PNDV was recovered from the brains of these died ducklings.However,the ducklings infected by intramuscular injection or nose/eye dropping had no any abnormality within 14 days post infection(PI),but the specific antibodies against NDV were detected by HI test(6～9)log 2),which declined markedly in a short time.No PNDV was isolated from the brains and the spleens of these ducklings.This test results show Pekin ducklings have low susceptibility to PNDV, the mortality of the ducklings infected experimentally by intravenous injection decline gradually with the increase of age.The PNDV_borne periods of the brains and the spleens of the ducklings inoculated by intramuscular injection or nose/eye dropping are not more than 14 days.