Sequence Analysis on NS2a-NS2b Gene of Dengue Virus Type 1 from Guangzhou City

Objective To confirme a case of dengue virus infection and chase the origin of infection by analyzing the DNA sequence of the isolated vims. Methods The nonstructural protein gene (NS2a-NS2b) of the isolated dengue virus type 1 strains was amplified by reverse Iranscriptase-polymerase chain reaction (RT-PCR), and then cloned into pMD18-T vector. DNA sequence was determined and analyzed. Results It was confirmed that the case was dengus virus type 1 infection. The sequence homology between NS2a-NS2b gene and GD01/04-GD23/95, GD01/04-GD14/97, GD01/04-GD05/99, and GD01/04-GD23/03 were 90.8%, 97.6%, 100% and 98.6% respectively. Conclusions The case is a dengus virus type 1 infection. The sequence of GD01/04 is the same as GD05/99 from the Zhongshan city in 1999, and shows a high homology with GD14/97 and GD23/03, indicating that they belong to the same genotype. The data shows that there may be an endemic origin of dengue virus type 1 in China.