PLoS Neglected Tropical Diseases (Sep 2021)

Assessment of fitness and vector competence of a New Caledonia wMel Aedes aegypti strain before field-release.

  • Nicolas Pocquet,
  • Olivia O'Connor,
  • Heather A Flores,
  • Jordan Tutagata,
  • Morgane Pol,
  • David J Hooker,
  • Catherine Inizan,
  • Sylvie Russet,
  • Johanna M Duyvestyn,
  • Etiene C Pacidônio,
  • Dominique Girault,
  • Daniela da Silva Gonçalves,
  • Marine Minier,
  • Frédéric Touzain,
  • Elodie Chalus,
  • Kevin Lucien,
  • Florie Cheilan,
  • Tristan Derycke,
  • Sylvie Laumond,
  • Cameron P Simmons,
  • Myrielle Dupont-Rouzeyrol,
  • Nadège Rossi

DOI
https://doi.org/10.1371/journal.pntd.0009752
Journal volume & issue
Vol. 15, no. 9
p. e0009752

Abstract

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BackgroundBiological control programs involving Wolbachia-infected Aedes aegypti are currently deployed in different epidemiological settings. New Caledonia (NC) is an ideal location for the implementation and evaluation of such a strategy as the only proven vector for dengue virus (DENV) is Ae. aegypti and dengue outbreaks frequency and severity are increasing. We report the generation of a NC Wolbachia-infected Ae. aegypti strain and the results of experiments to assess the vector competence and fitness of this strain for future implementation as a disease control strategy in Noumea, NC.Methods/principal findingsThe NC Wolbachia strain (NC-wMel) was obtained by backcrossing Australian AUS-wMel females with New Caledonian Wild-Type (NC-WT) males. Blocking of DENV, chikungunya (CHIKV), and Zika (ZIKV) viruses were evaluated via mosquito oral feeding experiments and intrathoracic DENV challenge. Significant reduction in infection rates were observed for NC-wMel Ae. aegypti compared to WT Ae. aegypti. No transmission was observed for NC-wMel Ae. aegypti. Maternal transmission, cytoplasmic incompatibility, fertility, fecundity, wing length, and insecticide resistance were also assessed in laboratory experiments. Ae. aegypti NC-wMel showed complete cytoplasmic incompatibility and a strong maternal transmission. Ae. aegypti NC-wMel fitness seemed to be reduced compared to NC-WT Ae. aegypti and AUS-wMel Ae. aegypti regarding fertility and fecundity. However further experiments are required to assess it accurately.Conclusions/significanceOur results demonstrated that the NC-wMel Ae. aegypti strain is a strong inhibitor of DENV, CHIKV, and ZIKV infection and prevents transmission of infectious viral particles in mosquito saliva. Furthermore, our NC-wMel Ae. aegypti strain induces reproductive cytoplasmic incompatibility with minimal apparent fitness costs and high maternal transmission, supporting field-releases in Noumea, NC.