The Construction and Characterization of an Infectious Clone of the Asian Genotype Chikungunya Virus from Yunnan, China

Chikungunya fever (CHIKF), which is caused by the Chikungunya virus (CHIKV), has rapidly spread across the globe in recent years, leading to its listing as a public health concern by the World Health Organization. In 2019, the first local outbreak of Asian-type CHIKF was reported in Xishuangbanna, Yunnan Province, China, with 88 CHIKV nucleic acid-positive cases detected from clinical specimens. To further investigate the biological characteristics of the virus strain responsible for this outbreak, we reconstructed the 625D6h strain using reverse genetics and tested its growth kinetics in different cell lines. The results showed a strong replication capacity in the <i>Aedes albopictus</i> C6/36 insect cell line but a weaker one in mammalian cell lines. The virus's high replication capacity in mosquito cells is an interesting phenotype that warrants further study to determine if it influences vector adaptation and transmission dynamics in endemic settings. The study also found that two DHODH inhibitors, ML390 and vidofludimus, could effectively inhibit CHIKV replication in vitro. The infectious clone created in this study provides a useful tool for studying the recently prevalent Asian-type strain in China, supporting the subsequent development of prevention and treatment methods.