Isolation, Identification Of Mink Enteritis Virus And Preparation Of Immunoglobulin

Mink infectious enteritis that is also known as mink viral enteritis, caused an acute, high contact and fatal disease by Mink enteritis virus (MEV). This disease is widespread in the world and one of the greatest diseases in mink farm. Currently although mink populations have been widely with vaccine immunity, mink infectious enteritis still occurred. And the treatment mainly is symptomatic treatment, there is no effective therapy. Therefore it is necessary to comprehensively study the biological characteristics and understand the infection situation of MEV in China, and conduct anti-MEV antibody research. MEV samples were collected from infected mink according to the clinical symptoms. The embryonic feline kidney cell line F81 was used to multiplicate the virus. HA, PCR and other methods were used to identify the MEV. Three pairs of primers were designed and used to amplify VP2 gene of isolated virus and mink samples from Dalian, the homology of nucleotide were analyzed. On this basis laying hens were immunized by MEV samples to prepare the egg yolk antibodies (IgY). Chloroform method and ammonium sulphate method were used to the purified IgY. And it was tested with HI. Finally a virulent strain was successfully isolated and named MEV-ZYL-1 with good immunogenicity. The nucleotide homology with the isolated virus and mink samples from Dalian is 100%. The full length of the VP2 is 1755bp, which encodes 584 amino acids, with the same length as the VP2 gene of standard strain MEV-type2 of MEV. The study of genetic evolution indicated that MEV-ZYL-1 has a closer relationship with strain Manzhouli and Suning in 2009. Accession number sequence is GU272028,GU272029 in Genebank. We identified MEV-ZYL-1 is a major epidemic MEV strain in China for it had close relationship with Manzhouli and Suning strains which had been isolated in 2009. MEV-ZYL-1 then inactivated to immunized to healthy lay egg chicken, IgY was purified by chloroform method and ammonium sulphate method, HI test showed the antibody level increased with the number of immunization times. HI is 1:1024 after the third immunization. Two infected mink were cured and the protection rate reached to 100%.The present research suggests that anti-MEV IgY have the potential for further development and use of MEV treatment.