Work

Replication variance of African and Asian lineage Zika virus strains in different cell lines, Aedes aegypti mosquitoes and neonatal mice

Year: 2020

Type: article

Abstract: Background: The Zika virus (ZIKV) is a mosquito-borne virus that was first isolated from the blood of non-human primates in the Zika forest in Uganda, 1947. ZIKV is divided into two phylogenetic lineages, African and Asian. Recently, Asian-lineage ZIKV was linked to the spread across the Pacific Islands and the Americas and the associated birth defects and neurological disorders. In Cambodia, ZIKV was found in circulation since 2007 and belonged to Asian lineage. However, the virus and the associated diseases remain poorly documented in this country. The aim of our study was to investigate replication and phenotypic differences in vitro and in vivo of three ZIKV strains from the two lineages. Methods & Materials: We analyzed the growth of African lineage ZIKV strain (HD78788, Senegal) and two Asian lineages ZIKV strains (NC2014-5132 from New Caledonia and FSS 13025 from Cambodia) in different mosquito cell lines as well as in a mammalian cell line, and determined the vector competence of two different Cambodian field-collected A. aegypti populations (Phnom Penh as urban vs. Kampong Cham as rural) and studied virulence and pathogenesis of the three ZIKV strains using neonatal Swiss mice. Results: We observed a significant higher pathogenicity of the African strain in vitro (cytopathic effect in Aag2, C6/36, Vero cells), and in vivo in both A. aegypti populations and mice (reduced survival rate). Both mosquito populations were competent to transmit all ZIKV as early as 7 days p.i. depending on the population and the ZIKV strains. These mosquitoes from rural habitat showed significant higher transmission and survival rates than A. aegypti from urban Phnom Penh in all three virus strains. We found the African ZIKV isolate had better transmission efficiency than Cambodian and New Caledonian isolates particularly in the A. aegypti population from Phnom Penh. Conclusion: Overall, our results highlight the phenotypic differences of the ZIKV lineages and the potential risk of ZIKV transmission by Cambodian A. aegypti mosquitoes. Further investigations of Cambodian mosquito species and ZIKV-specific surveillance in humans is important to monitor their re-introduction/re-emergence and improve the local risk assessment.

Source: International Journal of Infectious Diseases

DOI: 10.1016/j.ijid.2020.09.1338