A new Tanay virus isolated from mosquitoes in Guangxi, China

In 2013, seven virus strains were isolated from Culex tritaeniorhynchus and C. quinquefasciatus collected in Guangxi Province, China. The viruses caused cytopathological effects (CPE) only in C6/36 cells, and not in mammalian cells, e.g. BHK21 and Vero cells. Comparative genomic analysis revealed that the genomes of the seven virus strains ranged from 9589 to 9595 nt with G+C contents of 37.51-37.59%, and nucleotide sequence similarity > 99.8%. The nucleotide sequence homology of the seven virus strains with a Tanay virus isolate was 79.8-80.0%, while the corresponding amino acid homology of ORF1, ORF2, and ORF3 was 79.8-80, 73.9-4.6, and 93.4-94.3%, respectively. In phylogenetic analysis, based on the RdRP amino acid sequence, the seven virus strains were located on the same evolutionary branch, yet distinct from Tanay virus isolated from the Philippines. These results indicated that the seven virus strains isolated from Guangxi represent a new Tanay virus, "Tanay-like virus", within the genus Sandewavirus of the newly proposed taxon Negevirus. This was the first isolation of Tanay virus in China.