[Isolation and identification of a Banna virus strain from mosquitoes in Yunnan province].

Objective: To isolate and identify Banna virus (BAV) from mosquitoes collected in Mengla county of Yunnan province.

Methods: Mosquito samples were collected in houses and stock yards in Mengla county, 2008. Mosquitoes were homogenized and incubated onto both C6/36 and BHK21 cells. The new isolate was identified by using ELISA and RT-PCR. The sequences of segment 5, 8 and 11 of BAV were amplified by RT-PCR and determined. Phylogenetic analysis on the new BAV were performed using MEGA4 program.

Results: 1731 mosquitoes representing 7 species were collected with one strain of BAV isolated and identified. Phylogenetic analysis based on sequences of segment 8 showed the new isolate was closed to BAV strain isolated in Yunnan, but segment 11 sequence was closed to Vietnam strain.

Conclusion: Results of phylogenetic analysis implied that the BAV re-assortment might have been occurred both in Chinese and Vietnam strains.