Recharacterization of Morphological and Genetic Feature of Getah Virus Isolated from South Korea

Abstract

Three QIAG93 strains, QIAG9301, QIAG9302 and QIAG9303 that have been identified as Getah virus (GETV) are analyzed in this study. The morphological features of three virus isolates were observed by using electron microscopy, suggesting that the QIAG9301, QIAG9302 and QIAG9303 isolate can be classified as tentative member of Alphavirus species in the Semliki Forest complex. The full length of the structural polyprotein gene of each QIAG93 isolate (QIAG9301, QIAG9302 and QIAG9303) was determined that are identical in size, comprising 3759 nucleotides that encoded 1253 amino acids. The sequence analysis of the structural polyprotein gene, including the C, E3, E1, 6K and E2 domain, showed that each QIAG93 isolate shares >98.9% sequence identity. The phylogenetic analysis and evolutionary distance (ED) estimation based on the structural polyprotein gene sequence showed that the QIAG9301 isolate is closely related to GETV South Korea strain (99.9% sequence identity and ED value 0.001) and Chinese GETV YN0540 strain (99.3% sequence identity ED value 0.007) than other Alphavirus species analyzed in this study. Both QIAG9032 and QIAG9303 isolate exhibited genetically close relationship with Mongolian GETV LEIV17741MPR strain (at least 99.3% sequence identity and mean ED value 0.0065). Therefore, our findings will be valuable for molecular epidemiological analyses of GETV in Korea and contribute to a further study on pathogenicity of three QIAG93 isolates in animals.