title: Phylogenetic relationships and pathogenicity variation of two Newcastle disease viruses isolated from domestic ducks in Southern China.
abstract: BACKGROUND
  Newcastle disease (ND) is an OIE listed disease caused by virulent avian paramyxovirus type 1 (APMV-1) strains, which is enzootic and causes large economic losses in the poultry sector. Genotype VII and genotype IX NDV viruses were the predominant circulating genotype in China, which may possibly be responsible for disease outbreaks in chicken flocks in recent years. While ducks and geese usually have exhibited inapparent infections.
  
  
  METHODS
  In the present study, we investigate the complete genome sequence, the clinicopathological characterization and transmission of two virulent Newcastle disease viruses, SS-10 and NH-10, isolated from domestic ducks in Southern China in 2010.
  
  
  RESULTS
  F, and the complete gene sequences based on phylogenetic analysis demonstrated that SS-10 (genotype VII) and NH-10 (genotype IX) belongs to class II. The deduced amino acid sequence was (112)R-R-Q-K/R-R-F(117) at the fusion protein cleavage site. Animal experiment results showed that the SS-10 virus isolated from ducks was highly pathogenic for chickens and geese, but low pathogenic for ducks. It could be detected from spleen, lung, kidney, trachea, small intestine, bursa of fabricius, thymus, pancreas and cecal tonsils, oropharyngeal and cloacal swabs, and could transmit to the naive contact birds. Moreover, it could transmit to chickens, ducks and geese by naive contact. However, the NH-10 virus isolated from ducks could infect some chickens, ducks and geese, but only caused chickens to die. Additionally, it could transmit to the naive contact chickens, ducks, and geese.
  
  
  CONCLUSIONS
  The two NDV isolates exhibited different biological properties with respect to pathogenicity and transmission in chickens, ducks and geese. Therefore, no species-preference exists for chicken, duck or goose viruses and more attention should be paid to the trans-species transmission of VII NDVs between ducks, geese and chickens for the control and eradication of ND.
authors.forename: Yinfeng
authors.initials: Y
authors.lastname: Kang
authors.forename: Yanling
authors.initials: Y
authors.lastname: Li
authors.forename: Runyu
authors.initials: R
authors.lastname: Yuan
authors.forename: Xianwei
authors.initials: X
authors.lastname: Li
authors.forename: Minhua
authors.initials: M
authors.lastname: Sun
authors.forename: Zhaoxiong
authors.initials: Z
authors.lastname: Wang
authors.forename: Minsha
authors.initials: M
authors.lastname: Feng
authors.affiliation: National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China. prjiao@yahoo.com.
authors.forename: Peirong
authors.initials: P
authors.lastname: Jiao
authors.forename: Tao
authors.initials: T
authors.lastname: Ren
mesh_terms: D000818:Animals; D002645:Chickens; D002681:China; D004196:Disease Outbreaks; D004372:Ducks / Q000821:virology*; D005777:Geese; D016679:Genome, Viral; D008969:Molecular Sequence Data; D009521:Newcastle Disease / Q000635:transmission / Q000821:virology*; D009522:Newcastle disease virus / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D016366:Open Reading Frames; D011201:Poultry Diseases / Q000635:transmission / Q000821:virology*; D012367:RNA, Viral; D017422:Sequence Analysis, DNA; D014774:Virulence / Q000235:genetics
chemical_list: D012367:RNA, Viral