title: Genetic diversity analysis of the ORF5 gene in porcine reproductive and respiratory syndrome virus samples from South China.
abstract: To understand the genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) in South China, we collected 231 clinical samples from pigs with suspected PRRSV infection in Guangdong between 2007 and 2009. We found that 74 of 231 samples were positive by RT-PCR. The PCR products of the ORF5 gene of 35 isolates from different farms were sequenced and their DNA sequences were compared to 23 other PRRSV isolates in the GenBank. We found that the nucleotide similarity among all South China isolates ranged from 87.6% to 100%, and all belonged to the North American genotype. Most of them were classified into subgenotype I, but the rest mapped to subgenotypes III, V or VI. Those in subgenotypes I and III were found to be highly variable in the primary neutralising epitope (PNE) with a specific amino acid mutation (F39/L39→I39), and a few isolates in subgenotypes I and III isolates also had a mutation at L41 (L41→S41). PRRSV isolates in subgenotypes III, V and VI had less potential glycosylation sites than those in subgenotype I. Our data contribute to the understanding of molecular variation of PRRSV in South China.
authors.affiliation: South China Agricultural University College of Veterinary Medicine, Guangzhou, China.
authors.forename: Zong-Xi
authors.initials: ZX
authors.lastname: Cao
authors.forename: Pei-Rong
authors.initials: PR
authors.lastname: Jiao
authors.forename: Yu-Mao
authors.initials: YM
authors.lastname: Huang
authors.forename: Hong-Yang
authors.initials: HY
authors.lastname: Qin
authors.forename: Liu-Wu
authors.initials: LW
authors.lastname: Kong
authors.forename: Quan-Hui
authors.initials: QH
authors.lastname: Pan
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: He
authors.forename: Gui-Hong
authors.initials: GH
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002681:China / Q000453:epidemiology; D015967:Gene Expression Regulation, Viral; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000453:epidemiology / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics*; D013552:Swine; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D014759:Viral Envelope Proteins; D014764:Viral Proteins; C114789:glycoprotein 5, PRRSV