title: [Nucleotide sequencing of E/NS1 gene segment of dengue type 1 viruses isolated in Guangdong Province].
abstract: OBJECTIVE
  To analyse the genetic relationship of local strains of dengue type 1 viruses isolated in different years and regions from Guangdong Province, and to explore the genetic links with strains of adjacent countries by comparing with the sequences of relevant strains in Genbank.
  
  
  METHODS
  The viral RNAs were extracted and used for one-step reverse transcriptase polymerase chain reaction (RT-PCR) to amplify the partial nucleotide fragments in E/NS1 gene junction which were then cloned into the plasmid pBluescript II SK for sequencing, the results were analysed by DNASTAR software.
  
  
  RESULTS
  The phylogenetic tree of the sequenced 14 strains of dengue type 1 viruses branches into two genotypic groups. The nucleotide sequences showed a maximal homologies of 99.2% with Indonesia strains, 100% with Philippines strains and 98.8% with Thailand strains.
  
  
  CONCLUSIONS
  The dengue type 1 viruses of Guangdong Province are closely related to the Philippines, Indonesia and Thailand strains, which may indicate the possibility of importation from those countries.
authors.affiliation: Center for Disease Control and Prevention of Guangdong Province, Guangzhou 510300, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Zheng
authors.forename: Limin
authors.initials: L
authors.lastname: Jiang
authors.forename: Huiming
authors.initials: H
authors.lastname: Luo
authors.forename: Jianfeng
authors.initials: J
authors.lastname: He
authors.forename: Xinmin
authors.initials: X
authors.lastname: Dong
mesh_terms: D001483:Base Sequence; D002681:China; D003716:Dengue Virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005814:Genes, Viral / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid