%0 Journal Article
%T Phylogenetic analysis and molecular characteristics of seven variant Chinese field isolates of PRRSV
%A Chengmin Wang
%A Bin Wu
%A Said Amer
%A Jing Luo
%A Hongmei Zhang
%A Yunhai Guo
%A Guoying Dong
%A Baohua Zhao
%A Hongxuan He
%J BMC Microbiology
%D 2010
%I BioMed Central
%R 10.1186/1471-2180-10-146
%X Five genes (GP2, GP3, GP4, GP5 and NSP2) of seven isolates of PRRSV from China, designated LS-4, HM-1, HQ-5, HQ-6, GC-2, GCH-3 and ST-7/2008, were sequenced and analyzed. Phylogenetic analyses based on the nucleotide sequence of the ORF2-5 and NSP2 showed that the seven Chinese isolates belonged to the same genetic subgroup and were related to the North American PRRSV genotype. Comparative analysis with the relevant sequences of another Chinese isolate (BJ-4) and North American (VR2332 and MLV) viruses revealed that these isolates have 80.8-92.9% homology with VR-2332, and 81.3-98.8% identity with MLV and 80.7-92.9% with BJ-4. All Nsp2 nonstructural protein of these seven isolates exhibited variations (a 29 amino acids deletion) in comparison with other North American PRRSV isolates. Therefore, these isolates were novel strain with unique amino acid composition. However, they all share more than 97% identity with other highly pathogenic Chinese PRRSV strains. Additionally, there are extensive amino acid (aa) mutations in the GP5 protein and the Nsp2 protein when compared with the previous isolates.These results might be useful to study the genetic diversity of PRRSV in China and to track the infection sources as well as for vaccines development.Porcine reproductive and respiratory syndrome virus (PRRSV) is recognized as one of the major infective agents in the pig industry worldwide since its appearance in the 1980s. It was first diagnosed in the USA in 1987 [1], immediately found in Europe, soon disseminated to the rest of the world [2]. The disease is characterized by reproductive failure in pregnant sows and respiratory distress particularly in suckling piglets, thereupon getting its name. PRRSV is a single-stranded positive RNA virus and a member of the family Arteriviridae in the order of Nidovirales [3]. Based on phylogenetic analyses of different virus isolates around the world, PRRSV can be differentiated into two genotypes: Type I, represented by the Europe
%U http://www.biomedcentral.com/1471-2180/10/146