Nucleotide sequencing of E/NS1 gene segment of dengue type 1 viruses isolated in Guangdong Province / 中华实验和临床病毒学杂志

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>