[Isolation, identification and sequence analyses of dengue virus type 2 strain GD19/2001].
OBJECTIVE
To identify the virus isolated from Jiangmen, Guangdong province and to discuss the possible origin.


METHODS
Using characteristics of indirect fluorescent antibody tests (IFA), reverse transcription-polymerase chain reaction (RT-PCR), mouse neurovirulence and cell culture to identify the isolated virus. According to the nature of dengue virus type 2 NGC strain, two pairs of primers were designed. The structural protein gene of isolated dengue virus type 2 strain was then amplified by RT-PCR, cloned into pMD18-T vector and sequenced.


RESULTS
Twenty-two of 37 serum samples showed a positive reaction to dengue antibody IgG, and 36 of 37 with IgM with the highest antibody titer 1:640. Ten samples were resulted in a cytopathy on C6/36 cells and showed a neurovirulence in suckling mice when inoculated intracerebrally. The structural gene of new isolate GD19/2001 containing 2 325 nucleotides which encoded 774 amino acids. Data on nucleotide homology were 98%, 96%, 94%, 94%, 92%, 92%, 92% and 91% compared with TSV01, GD06/93, NGC and 44, ThNH81/93, 04 and GD08/98, and S1 respectively.


CONCLUSIONS
The isolated virus from Jiangmen, Guangdong province belonged to dengue virus type 2, which might come from Australia.
Ren
Rui-wen
RW
The Military Medical Institute of Guangzhou Military District, Guangzhou 510507, China.
Fang
Mei-yu
MY
Hong
Wen-yan
WY
Huang
Bao-ming
BM
Jiang
Lian-hua
LH
Liu
Jian-wei
JW
Tian
Xiao-dong
XD
Cheng
Gang-feng
GF
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002681:China / Q000453:epidemiology; D004279:DNA, Viral / Q000235:genetics; D003715:Dengue / Q000453:epidemiology / Q000821:virology*; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D005455:Fluorescent Antibody Technique; D006801:Humans; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA
D000914:Antibodies, Viral; D004279:DNA, Viral; D012367:RNA, Viral