Arbovirology Working Group

Our work primarily focuses on controlling mosquito-borne virus transmission using Wolbachia. Wolbachia is an insect symbiotic bacterium that can persistently infect mosquito species such as Aedes aegypti (the major vector for viruses including dengue, Zika and chikungunya). When Ae. aegypti are infected with Wolbachia, the mosquitoes are significantly less likely to transmit important human pathogenic viruses such as dengue.

Objectives:

• To determine the mechanisms by which Wolbachia inhibits viruses in Ae. aegypti.
• To determine the risk of dengue and related viruses adapting to overcome Wolbachia.
• To explore the utility of Wolbachia in protecting against viruses transmitted by mosquito species beyond Ae. aegypti.

Over the last decade the Australian-led World Mosquito Program has established the use of Wolbachia as a biocontrol tool, deploying mosquitoes carrying the bacterium in regions of 12 dengue-prone countries to date. Wolbachia’s efficacy was recently demonstrated in a randomised controlled trial in Yogyakarta, Indonesia, where a 77% reduction in dengue incidence was reported in regions of the city where Wolbachia was established in Ae. aegypti populations (Utarini et al., NEJM 2021).

Our research is focussed on understanding the molecular mechanisms that underpin Wolbachia's antiviral activity in Ae. aegypti. Using novel in vivo and in vitro systems, we apply a range of molecular technologies including high resolution imaging, transcriptomics, proteomics and deep sequencing, to probe how Wolbachia modifies mosquito cells and how viruses like dengue may adapt to this antiviral pressure. This knowledge will help support the application and longevity of Wolbachia as an intervention strategy and may guide development of new applications for its use in other viral vector species.

We collaborate with a range of external partners located around Australia, including at the World Mosquito Program, Monash University, University of Melbourne, Flinders University and La Trobe University.

Antiviral Wolbachia strains associate with Aedes aegypti endoplasmic reticulum membranes and induce lipid droplet formation to restrict dengue virus replication.
Loterio RK, Monson EA, Templin R, de Bruyne JT, Flores HA, Mackenzie JM, Ramm G, Helbig KJ, Simmons CP, Fraser JE. (2023)
mBio, e0249523.

Enhancing the scalability of Wolbachia-based vector-borne disease management: time and temperature limits for storage and transport of Wolbachia-infected Aedes aegypti eggs for field releases.
Allman MJ, Lin YH, Joubert DA, Addley-Cook J, Mejia-Torres MC, Simmons CP, Flores HA, Fraser JE. (2023)
Parasit Vectors, 16(1), 108.

Novel Wolbachia-transinfected Aedes aegypti mosquitoes possess diverse fitness and vector competence phenotypes.
Fraser JE, De Bruyne JT, Iturbe-Ormaetxe I, Stepnell J, Burns RL, Flores HA, O'Neill SL.
PLoS Pathog, 13(12), e1006751.