From ‘popcorn’ to blocking dengue transmission
- Seymour Benzer, while screening Drosophila Melanogaster (fruit fly) & looking for gene mutations that caused brain degeneration, came across a strain of Wolbachia bacteria that proliferated when the fly reached adulthood, bringing about its early death.
- This bacteria would pop up & proliferate like a popcorn in the fly’s brains.
- At the same time, Scott O’Neill, Australian scientist at Yale, was attempting to use Wolbachia bacteria to carry genes into insect populations, thereby reducing their disease (dengue & malaria) transmitting capacity.
- This led to the ‘Eliminate Dengue Program’ (www.eliminatedengue.com), an international not-for-profit collaboration that seeks to use Wolbachia bacteria for dengue control.
- Wolbachia-carrying Aedes aegypti mosquitoes, primary transmitter of dengue , are being field tested in northern Australia. In Vietnam &Indonesia, trials have begun. Trials are planned in Brazil &Colombia too.
- When a male mosquito with Wolbachia mates with a female that lacks the bacteria, eggs laid do not hatch. A Wolbachia-infected female can, on the other hand, mate with either infected or uninfected males & produce progeny, that inherit the bacteria from her. As a result, when male and female mosquitoes carrying Wolbachia are released to breed with wild mosquitoes in any area, the bacteria will rapidly spread in among the mosquito population there.
- The bacteria greatly reduced the replication of dengue virus & its spread inside the mosquito body, which will reduce the risk of such mosquitoes from passing the virus to humans.
- A pipeline of new Wolbachia strains, with better fitness characteristics & stronger dengue blocking, was being developed & will go into trials over the next 2 years.
- A trial is being carried out in China on another mosquito, Aedes albopictus, by introducing an entirely new Wolbachia strain into it (This mosquito is already naturally infected with two Wolbachia strains).
- Wolbachia bacteria