In Vitro and In Vivo Characterization of a New Strain of Mosquito Flavivirus Derived from Culicoides

Mosquito-specific flaviviruses comprise a group of insect-specific viruses with a single positive RNA, which can affect the duplication of mosquito-borne viruses and the life growth of mosquitoes, and which have the potential to be developed as a vaccine platform for mosquito-borne viruses. In this study, a strain of mosquito flavivirus (MFV) YN15-283-02 was detected in Culicoides collected from Yunnan, China. The isolation of the purified MFV YN15-283-02 from cell culture failed, and the virus was then rescued by an infectious clone. To study the biological features of MFV YN15-283-02 in vitro and in vivo, electron microscopy, phylogenetic tree, and viral growth kinetic analyses were performed in both cell lines and mosquitoes. The rescued MFV (rMFV) YN15-283-02 duplicated and reached a peak in C6/36 cells at 6 d.p.i. with approximately 2 x 10(6) RNA copies/mu L (RNA to cell ratio of 0.1), but without displaying a cytopathic effect. In addition, the infection rate for the rMFV in Ae. aegypti show a low level in both larvae (<= 15%) and adult mosquitoes (<= 12%).

Automated summary

This study detected a strain of mosquito flavivirus (MFV) in Culicoides collected from Yunnan, China, and successfully rescued the virus using an infectious clone. Further analysis of the biological features of the virus in vitro and in vivo showed strong replication ability in cells but low infection rate in mosquitoes.