Dengue Exposure and Wolbachia wMel Strain Affects the Fertility of Quiescent Eggs of Aedes aegypti

Abstract

(1) Background: The deployment of the bacterium Wolbachia to reduce arbovirus transmission is ongoing in several countries worldwide. When Wolbachia-carrying Aedes aegypti are released and established in the field, females may feed on dengue-infected hosts. The effects of simultaneous exposure on life-history traits of Ae. aegypti to Wolbachia wMel strain and dengue-1 virus DENV-1 remain unclear. (2) Methods: We monitored 4 groups (mosquitoes with either DENV-1 or Wolbachia, coinfected with DENV-1 and Wolbachia, as well as negative controls) to estimate Ae. aegypti survival, oviposition success, fecundity, collapsing and fertility of quiescent eggs for 12 weeks. (3) Results: Neither DENV-1 nor Wolbachia had a significant impact on mosquito survival nor on mosquito fecundity, although the last parameter showed a tendency to decrease with ageing. There was a significant decrease in oviposition success in individuals carrying Wolbachia. Wolbachia infection and storage time significantly increased egg collapse parameter on the egg viability assay, while DENV-1 had a slight protective effect on the first four weeks of storage. (4) Conclusions: Despite limitations, our results contribute to better understanding of the tripartite interaction of virus, bacteria and mosquito that may take place in field conditions and aid in guaranteeing the Wolbachia strategy success.

Dengue Virus Serotype 1 Effects on Mosquito Survival Differ among Geographically Distinct Aedes aegypti Populations

“…Dead mosquitos were removed from the plastic vials and wing length was measured as the distance from the axillary incision to the apical margin, excluding the fringe [ 32 ]. This measurement was performed as a measure of mosquito body size as we are aware that it might influence insect survival and fecundity [ 14 , 18 , 19 , 33 , 34 , 35 ].…”

DENV-1 Titer Impacts Viral Blocking in wMel Aedes aegypti with Brazilian Genetic Background

“…Among the Wolbachia strains currently introgressed into Ae. aegypti , w Mel (from Drosophila melanogaster ) does not seem to influence mosquito fecundity and survival, but it reduces the oviposition success and the viability of eggs stored for many weeks under laboratory conditions [ 14 , 15 , 16 ]. Regarding the refractoriness to arboviruses, the w Mel strain inhibits the transmission of CHIKV [ 8 ], Yellow Fever [ 17 ], and Mayaro viruses [ 18 ], but its protective effect is not complete against DENV-1 [ 19 , 20 , 21 ] and ZIKV [ 22 ].…”

El cambio climático y el Aedes Aegypti: las estrategias contra el vector

“…Las intervenciones biológicas mediadas por Wolbachia o las técnicas de insectos estériles (TIE) para reducir la transmisión de arbovirus está en curso en varios países del mundo [7] . En Perú estas estrategias no han sido utilizadas aún para el control del dengue.…”