ChinaVirus Isolated in Guangdong, Complete Genome Sequence of a

, is the causative agent of chi-kungunyafever,whichischaracterizedbyfever,rash,myalgia,andarthralgia (7). CHIKV is transmitted to humans by infected mos-quitoes,andithasemergedandreemergedinAfrica,SouthAmer-ica, and Southern and Southeastern Asia, with a potential globalthreat to public health (1–3, 8). No licensed vaccine or antiviral isnow available for CHIKV infection.Although several imported cases of Chikungunya fever havebeen documented in China (12), no outbreak has ever been re-ported. However, a sudden chikungunya outbreak with 173 pa-tients was reported in Guangdong, China, in October 2010 (11).To date, no complete genome sequence of a Chinese CHIKVisolate has ever been reported. Here we report the complete ge-nome of CHIKV strain GD05/2010 isolated from the acute-phaseserum from a chikungunya patient in Guangdong, China. Thegenome RNA of CHIKV was extracted from viral culture inBHK-21 cells, and cDNA was produced by using Moloney murineleukemia virus (M-MLV) reverse transcriptase with a randomprimer. Sixteen primer pairs were used to generate the ampliconsthat spanned the entire viral genome. The 5= and 3= terminals ofthe viral genome were determined using 5= and 3=rapid ampli-fication of cDNA ends (RACE). All sequencing was carried outusing an ABI 3730 Sanger-based genetic analyzer, and one con-tig containing high-quality trace files was assembled usingDNASTAR version 7.0.The genome of CHIKV strain GD05/2010 is a positive singlestrandofRNAof11,811nucleotides(nt),anditcontainstwoopenreading frames (ORFs) embedded between the 5=and 3=untrans-lated regions. The first ORF, of 7,422 nt, encodes the nonstruc-tural polyprotein (consisting of nsP1, 2, 3, and 4), and the secondORF, of 3,744 nt, encodes the structural proteins (consisting of C,E2,E3,andE1).TheuntranslatedjunctionregionbetweenthetwoORFs is 65 nt in length.Three phylogenetically distinct groups of CHIKV with distinctantigenic properties have been identified, namely the Asian geno-type,theWestAfricangenotype,andtheEast,Central,andSouth-ern African (ECSA) genotype (1, 5, 6). Genome-scale phyloge-netic analysis was performed by using MEGA5.0 with theneighbor-joining method, and the results demonstrated thatstrain GD05/2010 belonged to the homogeneous Indian OceancladeoftheECSAgenotype.PhylogeneticanalysisbasedontheE1sequence also supported this conclusion. Sequence analysis of theE1 gene shows that GD05/2010 has 99.5%, 99.4%, and 97.1%nucleotide identities to SGEHICHS277108 isolated in Singapore(FJ445510), LR2006_OPY1 isolated in Reunion (DQ443544), andthe S27-African prototype (AF369024), respectively. Recombina-tion analyses within CHIKV strains were performed with SimPlotsoftware (4), and no obvious recombinant event was observed.Notably, the single-amino-acid mutation (A226V) in the E1 pro-tein that determined infectivity and vector specificity (9, 10) waspresent in this Chinese strain.The first outbreak of chikungunya fever in China has arousedwide public concerns. The complete genome of a Chinese CHIKVstrain is important for future surveillance and research for thisemerging arboviral infection in China.