title: [Molecular epidemiologic analysis on new emerged type 3 dengue virus in Guangzhou in 2009].
abstract: OBJECTIVE
  To analyze and trace the infection source the envelope (E) gene of the new emerged type 3 dengue virus in Guangzhou in 2009.
  
  
  METHODS
  Sera were collected from patients infected with local dengue fever. Dengue virus was cultured and isolated by C6/36 cells. The whole length E gene was amplified from the positive specimen by RT-PCR, thereby sequenced and phylogenetic tree drawn by neighbor-joining method. Both data on epidemiologic and molecular studies were processed and analysed.
  
  
  RESULTS
  7 strains of type 3 dengue virus were isolated from samples of the 19 patients. E gene of these strains was amplified. The complete E genes of 7 strains belonged to 1479 nucleotides in length, encoding a polyprotein of 493 amino acids. Data from the phylogenetic analysis showed that 09/GZ/1081, 09/GZ/1483 and 09/GZ/10806 strains fell within the Southeast Asia/South Pacific group. 09/GZ/10616, 09/GZ/11144, 09/GZ/11194 while 09/GZ/13105 strains fell within the India group.
  
  
  CONCLUSIONS
  The type 3 dengue virus identified in Guangzhou area in 2009 was imported and could be decided into two genotypes.
authors.affiliation: Guangzhou Center for Disease Control and Prevention, Guangzhou 510080, China.
authors.forename: Biao
authors.initials: B
authors.lastname: DI
authors.forename: Zhi-jun
authors.initials: ZJ
authors.lastname: Bai
authors.forename: Yu-lin
authors.initials: YL
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Luo
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Li-yun
authors.initials: LY
authors.lastname: Jiang
authors.forename: Zhi-cong
authors.initials: ZC
authors.lastname: Yang
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
mesh_terms: D002681:China / Q000453:epidemiology; D003715:Dengue / Q000453:epidemiology* / Q000821:virology*; D003716:Dengue Virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D004196:Disease Outbreaks; D005814:Genes, Viral; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D010802:Phylogeny; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: C084188:E protein, Dengue virus type 3; D014759:Viral Envelope Proteins