Phylogenetic analysis of the E gene of Dengue virus isolated in Guangdong province from 2006 to 2007 / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the genetic relationship of the Dengue virus strains isolated in Guangdong province in 2006 and 2007, and to find the sources of these virus. Methods Serum samples of the dengue fever patients from 5 cities of Guangdong province in 2006 and 4 cities in 2007 were collected. Three pairs of primers that specific for amplifying the 3 overlap fragments of E gene of Dengue virus type Ⅰ were designed. RNAs were extracted from C6/36 cells treated with patients' serum. E genes were amplified by RT-PCR, purified and then sequenced directly. To obtain the E gene complete sequences, the raw sequences were assembled and edited. Obtained E genes were compared with E genes of other Dengue virus type Ⅰ published in the GenBank, analyzed by MEGA version 4.1 software. Results In 2006, virus circulating in Guaogzhou2006(EF508203) was closest to Vietnam2006(EU482539) with 99.3% nucleotides homology, Chaozhou2006 (EF508206) and Shantou2006 (EF508207) strains were closest to Japan2004 (AB178040) and Singapore2006 (EU081280) with 99.5% nucleotides homology, while Yangjiang2006 (EF508205) and Yangjiang2001 (EF508200) were closest to each other and both with 99.5% nucleotides homology to Thailand2001 (AY732482). All 4 Dengue virus strains circulated in 2007 were closest to Singapore2005(EU081276) with 99.7% nueleotides homology. Conclusion The Dengue viruses prevalent in 2006 were from different sources while those in 2007 came from the same origin. The data also showed that there was an endemic area of Dengue virus in Guangdong province.