Abstract: In order to understand the pathogenicity of PRRSV about Nsp2 gene deletion mutant,The PRRS negative healthy piglets of 20 days-old were inoculated by intranasal with a Mutant of PRRSV Hn-2(GenBank:FJ237419)and Hn-4(GenBank:FJ237421)strains respectively,which delete 3 base pairs and 89 base pairs in the Nsp2 gene respectively,while healthy piglets were used for control,the sera were separated aseptically on the 0,7,14,24,32,41,50,60,70 d respectively,using RT-PCR to detect the virus,using ELISA method and immunofluorescence inhibition test for detection of anti-PRRSV N protein antibody and neutralizing antibodies,variation of the virus and antibody were comparied in different periods of time.The results showed that the PRRSV could be detected in 7-14 d after infected with the Mutant Hn-2,and Hn-4 strain,anti-PRRSV N protein antibodies could be detected on the 7th day and has maintained a high level,respectively,the low level of neutralizing antibodies could be detected respectively on 41 d and 50 d,and the neutralization antibody increased gradually.The test pigs were not of death,indicating that the mutant PRRSV with deleted Nsp2 gene does not necessarily lead to pig death.

Key words: PRRSV, N protein, neutralization antibody, Nsp2 gene

CLC Number: 

• S852.65

• Q78