title: Phylogenetic study of dengue-3 virus in Taiwan with sequence analysis of the core gene.
abstract: Dengue virus serotype 3 (dengue-3) has been classified into five genotypes (I-V) by phylogenetic analysis based on different viral genes. To investigate the genetic variability and evolutionary character of the dengue-3 isolates in southern Taiwan from 2005 to 2006, we analyzed the 290 nucleotides of the core (C) gene of 12 dengue-3 isolates and compared them with the published C gene sequences of global dengue-3 strains available in GenBank, including four isolates from 1998 and one isolate from 1999, from Taiwan. The dengue-3 viruses from 2005 to 2006 were not from continuous spread of an epidemic strain or re-emergence of the 2005 strains in the 2-year period because there was a 5.4-6.2% difference in the 290 nucleotides of the C gene and different genotypes between the 2005 and 2006 strains. Most of the nucleotide changes, compared with a prototype dengue-3 virus, H87, occurred in the third codon position and were non-synonymous mutations occurring naturally in the C gene. In addition, there was no consistent difference in the 290 nucleotides of the C gene between eight dengue fever and two dengue hemorrhagic fever isolates from 2006. The phylogenetic analysis indicates that the isolates from the 1998, 1999 and 2006 Taiwan dengue-3 epidemics are phylogenetically related and belong to genotype III. It was noted that the 2005 Taiwan dengue-3 isolates belong to another genotype. This molecular epidemiology study of dengue-3 viruses in Taiwan helps to elucidate whether there is a continuation of outbreaks in consecutive years, re-emergence of endemic dengue virus, or introduction of strains from other countries.
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Tung
authors.forename: Kuei-Hsiang
authors.initials: KH
authors.lastname: Lin
authors.forename: Ko
authors.initials: K
authors.lastname: Chang
authors.forename: Liang-Yin
authors.initials: LY
authors.lastname: Ke
authors.forename: Guan-Ming
authors.initials: GM
authors.lastname: Ke
authors.forename: Po-Liang
authors.initials: PL
authors.lastname: Lu
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Yen-Hsu
authors.initials: YH
authors.lastname: Chen
authors.forename: Horn-Che
authors.initials: HC
authors.lastname: Chiang
mesh_terms: D001483:Base Sequence; D003716:Dengue Virus / Q000145:classification* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D013624:Taiwan; D014758:Viral Core Proteins / Q000235:genetics*
chemical_list: D014758:Viral Core Proteins