免疫鸡群新城疫病毒检测和分离的研究

Detection and Isolation of Newcastle Disease Virus in Immunized Chickens

关键词:  新城疫病毒  免疫鸡群  检测  防制

Key words:  newcastle disease virus  immunized chicken  detection  control

摘要:

以SPF鸡抗新城疫病毒(NDV)IgG为包被抗体(5μg/mL),兔抗NDVVero细胞培养纯化毒IgG为第二抗体(1:200~600),酶标记羊抗兔IgG(1:5000)为指示抗体建立间接夹心ELISA,检测实验免疫鸡、攻毒鸡及现地免疫鸡口腔或泄殖腔外分泌物。结果表明:新城疫无毒力V₄疫苗免疫后2d,口腔内病毒抗原随机检出率为4/10,第10天为10/10;泄殖腔为0~1/10,并持续18d以上。滴鼻攻毒后1d,口腔和泄殖腔内病毒抗原检出率分别是8/10和6/10;第13天,泄殖腔内病毒抗原检出阴性。NDV灭活疫苗免疫60d后攻毒,第2天有7/20口腔和8/20泄殖腔检出阳性,并一直到攻毒后第14天。非免疫对照鸡攻毒后第3天直到死亡时,口腔和泄殖腔均可检出病毒抗原。对各地临床上无任何症状的NDV免疫鸡群检测发现,泄殖腔NDV抗原阳性率0%~9.3%,分离到8株NDV流行毒株,生物学试验证实这些毒株的毒力属中等毒力偏强或强毒。

Abstract:

An indirect sandwich enzyme linked immunosorbent assay (IS-ELISA) was described for detecting the viral antigens in the oral cavity or/and cloaca of NDV infected chicken by using the antibody (5μg/mL) of SPF chicken against NDV as captor,the antiserum (1:200~600) of rabbit anti-purified NDV reproduced with Vero cell as the second antibody,and the goat anti-rabbit IgG (1:5000) conjugated with peroxidase as indicator.The positive rate of the viral antigen in the cavity was 4/10;but lower(0~1/10) in the cloaca at the second day post vaccination with avirulent NDV₄,and lasted 18 days.While the immunized chicken was droped in nosal route,the protective efficiency was 100%.The viral antigens in the oral cavity and cloaca were positive at 8/10 and 6/10 respectively,but eliminated at only 13 days post-challenged in the oral cloaca.For 60-day immunized chicken with NDV oil emulsion of inactived vaccine,the positive rate of viral antigen in the oral cavity and cloaca was 7/20 and 8/20 respectively at the second day post-challenged,and lasted 14 days.But the non-immunized chicken was positive from the first day detecting to dead.The viral antigen in the cloaca from several chicken farms in different areas was positive ranging from 0% to 9.3% by IS-ELISA,and eight strains of NDV were isolated and distinguished.The biological studies showed their virulences belonging to mesogenic or velogenic strains.