[Identification of Nam Dinh virus in China]

During 2009-2012, the Nam Dinh virus (NDiv) was detected from the samples of Culex pipiens quinquefasciatus in Shenzhen China. In this study, cell culture,SYBR Green I based real time RT-PCR and RT-PCR were performed to analyze the cell susceptibility and other biological characteristics of the NDiV isolates. The results showed that C6/36 cell line was susceptible to four isolates of Culex pipiens quinquefasciatus. The "S" type amplification curve and specific melting curve were obtained in the realtime fluorescence quantitative RT-PCR based on SYBR Green I for the detection of the NDiV from the mosquito. The target bands from the RdRp gene and partial fragment of ZmHel1 gene were observed using agarose gel electrophoresis. Both the nucleotide and amino acid sequences of four Shenzhen isolates showed more than 99.00% homology with the Vietnam representative NDiV strain (02VN178). Phylogenetic analysis showed that four Shenzhen isolates shared the same evolution branch as the Vietnam representative NDiV strain. This is the first report of NDiV in China.