title: Genetic diversity of porcine reproductive and respiratory syndrome virus in Korea.
abstract: The high genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) has been an obstacle to developing an effective vaccine for porcine reproductive and respiratory syndrome (PRRS). This study was performed to assess the degree of genetic diversity among PRRSVs from Korean pig farms where wasting and respiratory syndrome was observed from 2005 to 2009. Samples from 786 farms were tested for the presence of PRRSV using reverse transcription PCR protocol. A total of 117 farms were positive for type 1 PRRSV while 198 farms were positive for type 2. Nucleotide sequences encoding the open reading frame (ORF) 5 were analyzed and compared to those of various published PRRSV isolates obtained worldwide. Sequence identity of the ORF 5 in the isolates was 81.6˜100% for type 1 viruses and 81.4˜100% for type 2 viruses. Phylogenetic analysis of the ORF 5 sequences showed that types 1 and 2 PRRSVs from Korea were mainly classified into three and four clusters, respectively. The analyzed isolates were distributed throughout the clusters independent of the isolation year or geographical origin. In conclusion, our results indicated that the genetic diversity of PRRSVs from Korean pig farms is high and has been increasing over time.
authors.affiliation: Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs, Anyang 430-757, Korea.
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Choi
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Song
authors.forename: Hee-Jong
authors.initials: HJ
authors.lastname: Song
authors.forename: Choi-Kyu
authors.initials: CK
authors.lastname: Park
authors.forename: Byounghan
authors.initials: B
authors.lastname: Kim
authors.forename: Yeun-Kyung
authors.initials: YK
authors.lastname: Shin
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D005814:Genes, Viral; D014644:Genetic Variation; D008168:Lung / Q000821:virology; D008198:Lymph Nodes / Q000821:virology; D016366:Open Reading Frames; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D056910:Republic of Korea; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D020539:Sequence Analysis, Protein / Q000662:veterinary; D013552:Swine
keywords: Korea; open reading frame 5; phylogenetic analysis; porcine reproductive and respiratory syndrome virus