Combining Wolbachia-induced sterility and virus protection to fight Aedes albopictus-borne viruses

PLoS Negl Trop Dis. 2018 Jul 18;12(7):e0006626. doi: 10.1371/journal.pntd.0006626. eCollection 2018 Jul.

Abstract

Among the strategies targeting vector control, the exploitation of the endosymbiont Wolbachia to produce sterile males and/or invasive females with reduced vector competence seems to be promising. A new Aedes albopictus transinfection (ARwP-M) was generated by introducing wMel Wolbachia in the ARwP line which had been established previously by replacing wAlbA and wAlbB Wolbachia with the wPip strain. Various infection and fitness parameters were studied by comparing ARwP-M, ARwP and wild-type (SANG population) Ae. albopictus sharing the same genetic background. Moreover, the vector competence of ARwP-M related to chikungunya, dengue and zika viruses was evaluated in comparison with ARwP. ARwP-M showed a 100% rate of maternal inheritance of wMel and wPip Wolbachia. Survival, female fecundity and egg fertility did not show to differ between the three Ae. albopictus lines. Crosses between ARwP-M males and SANG females were fully unfertile regardless of male age while egg hatch in reverse crosses increased from 0 to about 17% with SANG males aging from 3 to 17 days. When competing with SANG males for SANG females, ARwP-M males induced a level of sterility significantly higher than that expected for an equal mating competitiveness (mean Fried index of 1.71 instead of 1). The overall Wolbachia density in ARwP-M females was about 15 fold higher than in ARwP, mostly due to the wMel infection. This feature corresponded to a strongly reduced vector competence for chikungunya and dengue viruses (in both cases, 5 and 0% rates of transmission at 14 and 21 days post infection) with respect to ARwP females. Results regarding Zika virus did not highlight significant differences between ARwP-M and ARwP. However, none of the tested ARwP-M females was capable at transmitting ZIKV. These findings are expected to promote the exploitation of Wolbachia to suppress the wild-type Ae. albopictus populations.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / genetics
  • Aedes / microbiology*
  • Aedes / physiology*
  • Animals
  • Breeding
  • Chikungunya Fever / transmission
  • Chikungunya Fever / virology
  • Chikungunya virus / physiology
  • Dengue / transmission
  • Dengue / virology
  • Dengue Virus / physiology
  • Female
  • Humans
  • Infertility
  • Male
  • Mosquito Control / methods*
  • Mosquito Vectors / genetics
  • Mosquito Vectors / microbiology*
  • Mosquito Vectors / physiology*
  • Wolbachia / physiology*
  • Zika Virus / physiology
  • Zika Virus Infection / transmission
  • Zika Virus Infection / virology

Grants and funding

This project has received resources funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 731060 (Infravec2, Research Infrastructures for the control of vector-borne diseases; http://infravec2.eu/). Funding followed the positive evaluation of a formal request describing the research project which was prepared and submitted to Infravec2 by RM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.