Circulation and molecular characterization of Chikungunya virus (Togaviridae) reveals a new mutation (E2-N207D) in Espirito Santo, Brazil
Chikungunya virus (CHIKV) is an RNA virus from the family Togaviridae transmitted primarily by Aedes mosquitoes. The first report of CHIKV infection in Brazil dates to 2014; since then, the virus has become a major public health challenge. The main goal of this study was to perform a phylogenetic analysis of CHIKV isolates from febrile patients from Espirito Santo (ES) state during the 2017 outbreak to identify the genetic diversity of circulating CHIKV strains. CHIKV RT-qPCR confirmed cases were sequenced for phylogenetic relationship inferences and molecular characterization. Phylogenetic results showed that the virus in the 2017 ES outbreak belongs to the ECSA genotype. Molecular characterization revealed a new mutation in ES strains (E2-N207D). This variation generated an amino acid substitution by exchanging asparagine (N) for aspartate (D) at position 207 and it is associated with an anchoring groove, possibly interfering in viral envelope assembly and associated interaction with the target cell. Here we report a CHIKV-ECSA IIa outbreak that demonstrates the ES population's vulnerability to an Asian strain of this virus circulating elsewhere in Brazil. Despite the small sample size, this study describes phylogenetic data about CHIKV in ES state that helps expand of the virus genotype database, and reveals a new E2 protein CHIKV variant (E2-N207D). This data helps improve understanding of chikungunya fever in order to design efficient public health control strategies.