Chemotactic Activity of Products of Elizabethkingia anophelis Derived from Aedes albopictus against RAW264 Murine Macrophage Cell Line.

Dengue viruses enter the dermal macrophages derived from other tissues following a bite from an infected mosquito. We examined the chemotactic activity of factors derived from the dengue vector mosquito Aedes albopictus on a RAW264 murine macrophage cell line. We found that Elizabethkingia anophelis isolated from the mosquitoes exhibits migration-inducing activity in RAW264 cells. The active substances that induce the chemotactic movement were extracted using ethyl acetate. Chemotactic activity was noted in several of the fractions isolated using reverse-phase chromatography, suggesting that multiple components were responsible for this activity. Next, we isolated three bacterial colonies from wild A. albopictus mosquitoes collected from Toyama Park (Tokyo, Japan). The bacterial 16S rRNA gene sequences shared homology with that of Lonsdalea quercina. These bacteria also exhibited migration-inducing activity in RAW264 cells. The migration-inducing activity of the bacteria in mosquitoes may be a novel aspect of mosquito-mediated viral infections.