Study on attenuated Porcine reproductive and respiratory syndrome virus from highly pathogenic virus strain

Abstract

The attenuated porcine reproductive and respiratory syndrome virus was created from 90
continuously passage inoculation generations of the highly pathogenic KTY-PRRS-06 virus strain
on the Marc145 cell medium. The virus multiplied feature, viral titre, genetic characteristics of ORF5,
ORF7, NSP2 genes were determined in each of 10 passages. The piglets were inoculated with the
KTY-PRRS-06 virus at the 1st passages and 90th passages to test virulence of virus. The studied
results showed that the virus strain at the 90th passages exhibited cytopathogenic effect after 12
hours of infection and the cells were completely destroyed after 48 hours of infection. Viral titre,
ORF5, ORF7, NSP2 gene sequences were maintained stably from the 50th to 90th passages. This
attenuated virus strain did not cause disease in the experimental pigs and it h