Envelope gene evolution analysis on type 1, 2, 3 dengue virus in Guangzhou in 2010 / 中华传染病杂志

ABSTRACT

ObjectiveTo analyze the Envelope (E) gene of type 1,2,3 dengue virus isolated fromGuangzhouin2010, andtoinvestigatetheinfectionsourceandvirusgenotypes.MethodsEighty-five serum samples were collected from 85 patients in acute phase of dengue fever.Dengue virus was cultured and isolated by C6/36 cells.The whole length of E gene was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and then sequenced.The phylogenetic tree was drawn by neighbor-joining method.The bioinformatics analysis was performed by combining the phylogenetic information and the epidemiologic data.ResultsSix strains of type 1 dengue virus,two strains of type 2 dengue virus and six strains of type 3 dengue virus were isolated from 85 samples.The E gene sequence of these strains was obtained by sequencing.The phylogenetic analysis showed that type 1 and 3 dengue virus belonged to two genotypes (Asian and South Pacific ocean,India subcontinent and Southeast Asia/South Pacific ocean,respectively),and type 2 dengue virus belonged to one genotype (Malaysia/India subcontinent).ConclusionIt's presumed that all strains of type 2 dengue virus are imported,four strains of type 1 dengue virus are imported and four strains of type 3 dengue virus arc imported,the remaining two stains of type 1 and two stains of type 3 dengue virus need mosquito intermediary research further to prove their origins.