Wolbachia confers protection against the entomopathogenic fungus Metarhizium pingshaense in African Aedes aegypti

Authors: BILGO, ETIENNE - Institut National De La Sante Et De La Recherche Medicale (INSERM); MANCINI, MARIA - University Of Glasgow; GNAMBANI, EDOUNOU - Institut National De La Sante Et De La Recherche Medicale (INSERM); DOKPOMIWA, HOUEFFA - Institut National De La Sante Et De La Recherche Medicale (INSERM); MURDOCHY, SHIVAN - University Of Glasgow; Lovett, Brian; ST. LEGER, RAYMOND - University Of Maryland; SINKINS, STEVEN - University Of Glasgow; DIABATE, ABDOULAYE - Institut National De La Sante Et De La Recherche Medicale (INSERM)

Submitted to: Environmental Microbiology Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2024
Publication Date: 8/4/2024
Citation: Bilgo, E., Mancini, M.V., Gnambani, E.J., Dokpomiwa, H.A., Murdochy, S., Lovett, B.R., St. Leger, R.J., Sinkins, S.P., Diabate, A. 2024. Wolbachia confers protection against the entomopathogenic fungus Metarhizium pingshaense in African Aedes aegypti. Environmental Microbiology Reports. 16(4), e13316. https://doi.org/10.1111/1758-2229.13316.
DOI: https://doi.org/10.1111/1758-2229.13316

Interpretive Summary: Microbial symbionts, living inside of insects, play an important role in insect health and impact the success of control efforts. Wolbachia bacteria are by far the most important and impactful symbionts of medically important mosquitoes, with many studies characterizing these interactions and control methods leveraging their natural effects on mosquito mating and disease transmission. However, such studies are lacking when it comes to the efficacy of entomopathogenic fungi. In the Dengue fever Mosquito, Aedes aegypti, Wolbachia was shown to confer protection to infection with fungi, with these benefits alarmingly increasing at warmer temperatures. This study underscores the need to consider the symbiotic microbes within an insect to accurately predict the success of biocontrol fungi. This finding relates broadly to insect pests, as most agricultural pests rely on symbiotic microbes for survival.

Technical Abstract: Symbiotic and pathogenic microorganisms such as bacteria and fungi represent promising alternatives to chemical insecticides to respond to the rapid increase of insecticide resistance and vector-borne disease outbreaks. This study investigated the interaction of two strains of Wolbachia, wAlbB and wAu, with the natural entomopathogenic fungi from Burkina Faso Metarhizium pingshaense, known to be lethal against Anopheles mosquitoes. In addition to showing the potential of Metarhizium against African Aedes aegypti wild-type populations, our study shows that the wAlbB and wAu provide a protective advantage against entomopathogenic fungal infections. Compared to controls, fungal-infected wAu and wAlbB-carrying mosquitoes showed higher longevity, without any significant impact on fecundity and fertility phenotypes. This study provides new insights into the complex multipartite interaction among the mosquito host, the Wolbachia endosymbiont and the entomopathogenic fungus that might be employed to control mosquito populations. Future research should investigate the fitness costs of Wolbachia, as well as its spread and prevalence within mosquito populations. Additionally, evaluating the impact of Wolbachia on interventions involving Metarhizium pingshaense through laboratory and semi-field population studies will provide valuable insights into the effectiveness of this combined approach.