%0 Journal Article
%T The Genomic and Pathogenic Characteristics of the Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Isolate WUH2
%A Bin Li
%A Liurong Fang
%A Suyan Liu
%A Yunbo Jiang
%A Huanchun Chen
%A Shaobo Xiao
%J ISRN Virology
%D 2014
%R 10.1155/2014/624535
%X To fully understand the extent of genetic diversity and pathogenesis of the highly pathogenic PRRSV found in China, we determined the genomic sequence of PRRSV WUH2; the pathogenicity of WUH2 was compared to the classical PRRSV isolate CH-1a. Our results showed that the WUH2 genome had a discontinuous deletion of 30 aa in Nsp2, a 1 nucleotide deletion located in both the 5¡ä and 3¡ä UTRs, and point mutations within GP5. Experimental infection demonstrated that PRRSV WUH2 reproduced the phenotype and symptoms of porcine high fever syndrome. Importantly, we found that there were differences in viral burden in the serum and tissues when comparing infections of the pathogenic isolate WUH2 to those of the classical isolate CH-1a. These data provide insight into the genomic diversity and altered pathogenicity of Chinese PRRSV isolates and help elucidate the evolution and potential pathogenic mechanisms of PRRSV. 1. Introduction Porcine reproductive and respiratory syndrome (PRRS) is a relatively new viral disease of swine, that is, characterized by severe reproductive failure in sows and respiratory distress in piglets and growing pigs. Since PRRS was first reported in the United States in 1987 and Europe in 1990 [1, 2], the disease has devastated the swine industry by causing tremendous economic losses around the world; it is now considered one of the most important diseases in countries with intensive swine industries [3¨C5]. PRRS is caused by the PRRS virus (PRRSV), a member of a group of enveloped, positive-sense RNA viruses in the Arteriviridae family [6]. The genome of PRRSV is approximately 15£¿kb containing nine open reading frames (ORFs) [7]. ORF1a and ORF1b encode for the RNA-dependent RNA polymerase and nonstructural proteins (Nsps: Nsp1¦Á, Nsp1¦Â, and Nsp2¨C12), respectively [8¨C10]. ORF2a, ORF2b, and ORFs 3 through 7 encode the viral structural proteins GP2, E, GP3, GP4, GP5, M, and N, respectively [7, 11]. PRRSV can be divided into European and North American genotypes, which share only about 60% nucleotide identity at the genomic sequence level [12]. Isolates from each genotype exhibit significant sequence variation, particularly in Nsp2 and ORF5 which represent the most genetically variable regions in the PRRSV genome [4, 13, 14]. PRRSV was first reported in 1995 and the first isolate was identified in mainland China in 1996. Since then, PRRS has become one of the most important swine diseases worldwide. Many isolates have been obtained within China from different regions and times. A porcine high fever syndrome caused by a highly pathogenic PRRSV
%U http://www.hindawi.com/journals/isrn.virology/2014/624535/