Research On Co-infection Of DENV-1 And DENV-2 In C6/36 Cells And Aedes Albopictus

In 2014,unexpected large dengue outbreak has attacked Guangdong,China.Laboratory diagnosis demonstrated majority caused by dengue virus serotype 1(DENV-1)and serotype 2(DENV-2),Which has aroused widespread concern.We used DENV-1 and DENV-2 isolated in Guangzhou in 2014 to research the interaction of co-infection among different serotypes of DENV in C6/36 cells and Aedes albopictus.The epidemiological characteristics of the virus provide a theoretical basis for the prediction of dengue virus transmission.The results of the research are as follows: 1.The interaction of DENV-1 and DENV-2 in C6/36 cellsWhen DENV-1 and DENV-2 infected C6/36 cells simutaneous,the copies number of DENV-1 and DENV-2 decreased,but only the copies number of DENV-2 decreased rapidly.When C6/36 cells first infected DENV-1 and with 12 h after reinfected DENV-2(super-infection),the copies number of DENV-2 was significantly decreased compared with that of single infection and was significantly decreased compared from that of simutaneous infection.When C6/36 cells first infected DENV-2 and with 12 h after reinfected DENV-1(super-infection),the copies number of DENV-1 had no significant decreased compared with that of single infection.The results of the experiment showed that DENV-1 and DENV-2 competition with each other,but mainly inhibited DENV-2 virus replication.2.The interaction of DENV-1 and DENV-2 in Ae.albopictusWhen the two serotypes of the dengue virus infected Ae.albopictus simutaneously the infection rate and transmission rate were both lower than that of the single infection,indicating that the two dengue virus had a competitive effect at the simultaneous infection.However the transmission rate of DENV-2 is higher than that of DENV-1.It could be predicted that the DENV-2 possesses a competitive advantage in co-infection of Ae.albopictus.Ae.albopictus infected DENV-1 and DENV-2 with a 6 daytime lag between first and second serotype(super-infection),which can be simultaneously detected in the midgut and salivary glands,indicating that the mosquitoes which carrying one serotype dengue virus can infect another serotype dengue virus by sucking the blood again,and may transmit the two types of dengue virus at one bite.This experiment had a better understanding of the interaction between different serotype of dengue viruses in cell and vector.It can provided a theoretical basis for predicting the prevalence of dengue fever.