title: Experimental infection of a newly emerging Korean type I porcine reproductive and respiratory syndrome virus isolate in colostrum-deprived pigs.
abstract: BACKGROUND
  Recently, new emergence of type I PRRSV has been reported in Korea by several research groups. Although specific subgroups of type I PRRSVs in Korea were observed in the previous phylogenetic analysis, there is a lack of information about the virulence of type I PRRSV recently isolated in Korea.
  
  
  METHODS
  One type I PRRSV isolate (G2446, 3 times passaged in primarily cultured pulmonary macrophages) in Korea was experimentally infected in colostrum-deprived pigs. The pathological and serological evaluations were performed and compared to type II PRRSV strain (CP07-401-9, 5 times passaged in MARC-145 cell lines)-infected pigs, for 21 days post challenge (dpc).
  
  
  RESULTS
  The pneumonia found in gross examination was more severe in type I PRRSV-infected pigs than type II PRRSV-infected pigs. Both groups showed bronchointerstitial pneumonia, mild multifocal perivascular lymphohistiocytic myocarditis and lymphadenopathy at 14 dpc. However, the unique histopathologic lesions were not found in the pigs experimentally infected with a Korean type I PRRSV isolate, when compared to previous data about classical pathology of PRRSV. The PRRS-specific antibodies were detected in the first week after challenge and viremia continued at least until 21 dpc in both groups.
  
  
  CONCLUSIONS
  The gross and histopathologic lesion in this study indicated that Korean type I PRRSV strain (G2446) caused classical PRRSV-specific lesions. Although this study evaluated one representative strain of Korean type I PRRSV, the results may provide information regarding the pathogenicity of type I PRRSV recently emerged in Korea.
authors.affiliation: Department of Veterinary Medicine Virology Lab, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Hye Kwon
authors.initials: HK
authors.lastname: Kim
authors.forename: Chul Seung
authors.initials: CS
authors.lastname: Lee
authors.forename: Bo Kyu
authors.initials: BK
authors.lastname: Kang
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Yeom
authors.forename: Hyoung Joon
authors.initials: HJ
authors.lastname: Moon
authors.forename: Seong Jun
authors.initials: SJ
authors.lastname: Park
authors.forename: Van Giap
authors.initials: VG
authors.lastname: Nguyen
authors.forename: Dae Sub
authors.initials: DS
authors.lastname: Song
authors.forename: Bong Kyun
authors.initials: BK
authors.lastname: Park
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D003126:Colostrum; D004195:Disease Models, Animal; D005838:Genotype; D006651:Histocytochemistry; D017563:Lung Diseases, Interstitial / Q000473:pathology / Q000821:virology; D008206:Lymphatic Diseases / Q000473:pathology / Q000821:virology; D009205:Myocarditis / Q000473:pathology / Q000821:virology; D011024:Pneumonia, Viral / Q000473:pathology / Q000821:virology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D056910:Republic of Korea; D013552:Swine; D014774:Virulence
chemical_list: D000914:Antibodies, Viral