Peritrophic membrane structure of Aedes aegypti (Diptera: Culicidae) mosquitoes after infection with dengue virus type 2 (D2-16681)

Abstract

The peritrophic membrane (PM) is a non-cellular tissue involved in the protection of midgut epithelium from mechanical damage and insults from pathogens. This study was carried out to determine the involvement of PM in mosquitoes after infection with dengue virus. Aedes aegypti (Diptera: Culicidae) mosquitoes were fed sucrose and human blood with and without dengue virus type 2 (D2-16681), and collected at 0.5, 1, 6, and 12 h, respectively. Specimens were prepared for examination under light and electron microscopy. The results showed that PM was produced only in the blood-fed mosquitoes. The infected blood meal induced the mosquitoes to produce PM in their midgut earlier and thicker than in mosquitoes with blood alone. The initial evidence of PM occurred at 1 h post-blood meal (PBM) as a matrix-like structure. By 6 h PBM, PM had become a layer, which persisted at 12 h. Among mosquitoes fed with blood alone, this structure was found only from 6 and 12 h PBM. Dengue virus type 2 induced different modifications of mosquito PM construction and structures, confirmed under an electron microscope.