Preparation Of Egg Yolk Antibodies Against Bovine Viral Diarrhea Virus (bvdv) And Research The Activeness To Neutralize Virus

Bovine Viral Diarrhea is world wide infection disease caused by Bovine Viral Diarrhea Virus (BVDV),which result in persistently infection (PI),many respiratory problems and reproductive,such as diarrhoea,mucosal disease or abortion in cattle,sheepand wild animals. An important condition for maintenance of BVDV in bovine populations is the inapparent infection characterised by immunotolerant and persistent infection (PI) which persistently eliminate toxicant and become the infection sources in cattle herd.With the expanding of Xinjiang cattle-raising scale, the cow virulent diarrhea's case assumes the trend of escalation, if we does not take the corresponding measure, will create the serious economic loss.At present,using anti-BVDV IgY to treate BVDV infection cow has not been reported.So,we mainly study the preparation of high titre egg yolk antibodies by immunizing layer hens with cytopathic (CP) and ncytopathic (NCP) Bovine viral diarrhea virus (BVDV), and carried on both in vitro and in vivo neutral activeness research to this egg yolk antibodies. This is useful for further epidemic prevention.BVDV reproduced in MDBK cells and the viruses were collected.The viruses were concentrated by PEG..TCID50 of concentrated BVDV was detected with immunoperoxidase monolayer assay (IPMA).Layer hens were immunized with CP BVDV and NCP BVDV,the egg yolk was treated with modified PEG6000 method.The titres of IgY was tested with agar spread method and indirect ELISA,the neutralizing antibody titer to NCP BVDV with immunoperoxidase monolayer assay (IPMA).Calfs have no clinical symptom were detected using the RT-nPCR method.Positive calfs were treated with anti- NCP BVDV IgY antibodies. After the treatment, uses nest type RT-nPCR to carry on the examination once more, and calculates the the effect to eliminate virus.The present research show that egg yolk was successfully treated with modified PEG 6000 method.The titer of IgY against both CP BVDV and NCP BVDV was tested as 1:32 by agar spread method,and against CP BVDV was 1:32000, against NCP BVDV was 1:40000 by indirect ELISA.Neutralizing antibody titer to NCP BVDV was 1×10-3. The clinical trial indicated that the anti-NCP BVDV IgY has achieved 100% to the calf cow inapparent infection elimination factor.The above showed results indicate that highly titred and neutralized IgY antibodies can be purified,and show good virus protection effects both in vitro and in vivo.The present research suggests that anti-NCP BVDV IgY have the potential for further development and use of BVD prevention and treatment.