Autor(es): Tsetsarkin Konstantin A, Vanl-ingham Dana L, McGee Charles E, Higgs Stephen

Resumo: Chikungunya virus (CHIKV) is an emerging arbovirus associated with several recent large-scale epidemics. The 2005-2006 epidemic on Reunion isl- that resulted in approximately 266,000 human cases was associated with a strain of CHIKV with a mutation in the envelope protein gene (E1-A226V). To test the hypothesis that this mutation in the epidemic CHIKV (strain LR2006 OPY1) might influence fitness for different vector species, viral infectivity, dissemination, - transmission of CHIKV were compared in Aedes albopictus, the species implicated in the epidemic, - the recognized vector Ae. aegypti. Using viral infectious clones of the Reunion strain - a West African strain of CHIKV, into which either the E1-226 A or V mutation was engineered, we demonstrated that the E1-A226V mutation was directly responsible for a significant increase in CHIKV infectivity for Ae. albopictus, - led to more efficient viral dissemination into mosquito secondary organs - transmission to suckling mice. This mutation caused a marginal decrease in CHIKV Ae. aegypti midgut infectivity, had no effect on viral dissemination, - was associated with a slight increase in transmission by Ae. aegypti to suckling mice in competition experiments. The effect of the E1-A226V mutation on cholesterol dependence of CHIKV was also analyzed, revealing an association between cholesterol dependence - increased fitness of CHIKV in Ae. albopictus. Our observation that a single amino acid substitution can influence vector specificity provides a plausible explanation of how this mutant virus caused an epidemic in a region lacking the typical vector. This has important implications with respect to how viruses may establish a transmission cycle when introduced into a new area. Due to the widespread distribution of Ae. albopictus, this mutation increases the potential for CHIKV to permanently extend its range into Europe - the Americas.

Imprenta: PLoS Pathogens, v. 3, n. 12, p. e201, 2007

Identificador do objeto digital: 10.1371/journal.ppat.0030201

Descritores: Chikungunya virus - Arbovirus ; Chikungunya virus - Cell ; Chikungunya virus - Cytopathology ; Chikungunya virus - Genome ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Transmission ; Chikungunya virus - Epidemic ; Chikungunya virus - Epidemiology ; Chikungunya virus - Public health

Data de publicação: 2007

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