Effect of double dengue serotypes infection in dengue mosquito (Aedes aegypti)

Abstract

We demonstrated the results of laboratory induced dengue virus infection more than 1 serotype in female Aedes aegypti through membrane feeding apparatus. Forty female mosquitoes were allowed to feed human blood contained 4 dengue serotypes at the concentration of 103 pfu/ml. One week after infection, dengue virus were detected by RT-PCR technique. Seven and two mosquitoes were positive for dengue serotype 3 and 4, respectively. Mix infection of dengue virus serotype 3 and 4 was found in 4 female mosquitoes. To determine the infectivity of dengue serotype 1 and 2, both serotypes were used to infect 46 female mosquitoes. Eight and two mosquitoes were infect with serotype 1 and 2, respectively while no co-infection of these two serotypes were observed. The results showed that difference in capability of infection between dengue serotype in mosquito. Furthermore, co-infection between dengue virus serotypes 3 (DEN 3) and chikungunya (CHIKV) virus was also determined in Ae. albopictus (C6/36) by one-step duplex reverse transcription polymerase chain reaction (D-RT-PCR). The D-RT-PCR showed positive for both viruses either infection with equal titer of multiplicity of infection of both viruses and infection with higher titer of CHIKV than DENV 3. In contrast, co-infection with DENV 3 higher titer than CHIKV was shown only positive D-RT-PCR dengue virus. We demonstrate that inhibition of CHIKV replication by DENV 3 depends on virus titer. Field studies of dengue infection rates in Ae. aegypti female obtained from various seasons also showed that dengue infection rate in the mosquito vector depended on time and season. Thus, this study provides the interaction between pathogen against the host cells, in the mosquito vector both in laboratory and in the field which could be applied for predicting the outbreak and furthermore for effectively controls these mosquitos borne disease in the future.