title: Identification and pathogenicity of a variant porcine epidemic diarrhea virus field strain with reduced virulence.
abstract: BACKGROUND
  Since 2010, a variant Porcine epidemic diarrhea virus (PEDV), which causes an acute, highly contagious, and devastating viral enteric disease with a high mortality rate in suckling pigs, broke out in China and spread rapidly to neighboring countries, even to the North America. This virus gradually became the main subtype of PEDV worldwide. However, there were no reports of mild pathogenicity of a variant porcine epidemic diarrhea virus in China.
  
  
  RESULTS
  In 2013, a PEDV-positive sample from a sow with very mild clinical sign was used to inoculate in Vero cells to isolate the virus. This PEDV field strain, designated FL2013 strain, was successfully propagated and genetically characterized. The phylogenetic trees based upon either the complete genome or S gene showed that the FL2013 strain belongs to the genogroup G2b. The S gene of FL2013 has a 7-aa deletion (FEKVHVQ) in the C-terminus comparison with the other G2 PEDV sequences. Further comparative pathology study indicated that the FL2013 strain had reduced virulence to newborn piglets.
  
  
  CONCLUSIONS
  A novel variant PEDV strain FL2013 with reduced virulence, as determined by the pathological study, was identified from east China. This strain is closely related to the genogroup-2 PEDV strains prevalent in the U.S. and China currently, but had a short deletion at the 3'-end of the spike gene.
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, 510006, Guangzhou, P R China. zhangxb@scau.edu.cn.|College of Animal Science, South China Agricultural University, 510642, Guangzhou, China. zhangxb@scau.edu.cn.
authors.forename: Xiangbin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Guangdong Wen's Group Academy, Guangdong Wen's Foodstuffs Group Co., Ltd., Xinxing, Guangdong, China. wenspanyf@163.com.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Guangdong Wen's Group Academy, Guangdong Wen's Foodstuffs Group Co., Ltd., Xinxing, Guangdong, China. wdd-1984@126.com.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Guangdong Wen's Group Academy, Guangdong Wen's Foodstuffs Group Co., Ltd., Xinxing, Guangdong, China. txy8211@163.com.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tian
authors.affiliation: Guangdong Wen's Group Academy, Guangdong Wen's Foodstuffs Group Co., Ltd., Xinxing, Guangdong, China. yanhua_song@163.com.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, 510006, Guangzhou, P R China. caoych@mail.sysu.edu.cn.
authors.forename: Yongchang
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D018352:Coronavirus Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D008969:Molecular Sequence Data; D009656:North America; D010802:Phylogeny; D053485:Porcine epidemic diarrhea virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017385:Sequence Homology; D064370:Spike Glycoprotein, Coronavirus / Q000235:genetics; D013552:Swine; D013553:Swine Diseases / Q000473:pathology* / Q000821:virology*; D014774:Virulence
chemical_list: D012367:RNA, Viral; D064370:Spike Glycoprotein, Coronavirus