| dc.description.abstract | Porcine reproductive and respiratory syndrome is a devastating disease that
causes heavy losses to the economy and the development of agriculture. In this
study, we aimed to assess genetic variation of the ORF5 gene and NSP2 gene
from 12 Vietnamese porcine reproductive and respiratory syndrome virus
(PRRSV) strains. ORF5 and NSP2 gene were amplified with specific primers. The
PCR amplicons were used as templates for sequencing. MEGA 6 program was
applied to assess the genetic variation and phylogenetic analysis. The
hydrophobicity of GP5 was analyzed by Kyte and Doolittle method.
Our results showed that the Vietnamese strains were separated into two clusters,
in which five strains BG/12, TG1/12, TG2/12, TG3/12, TG4/12 were grouped in
cluster 1 and the left strains were belonged to cluster 2. The N21 glycosylation
site (N→S) of GP5 sequence was mutated in five Vietnamese strains from cluster
1. The core sequence of the neutralizing epitopes (including five positions at H25,
Q27, I29, Y30 and N31) in GP5 was presented in all Vietnamese strains excepting
strain TG1/12. The hydrophobicity plots of GP5 revealed two amino acid positions
of BG/12 strain which was different from CH-1a strain and VR2332 strain
including in position 85 to 95 and position 100. There were 4 new amino acid
substitutions of NSP2 from Vietnamese PRRSV strains at positions A24V, V63A,
S198G and N201D. The identity of amino acid sequence between Vietnamese
PRRSV strains with Henan-1 strain (92-97%) was higher than VR2332 strain (81-
84%). Two putative epitopes ECVQGCCEHKGLLGSPD and LCQVIEDCCCHQNKTN
were highly conserved in Vietnamese PRRSV strains. The phylogenetic analysis of
ORF5 and NSP2 sequences of Vietnamese strains and other strains indicated that
the Vietnamese strains belong to type II.
Keywords: PRRS, ORF5, NSP2, Vietnam | en_US |
