A genetically modified fungus killed huge numbers of malaria-carrying mosquitoes in a trial that took place in a fake village set up by researchers in Burkina Faso, West Africa.
Fungus Genetically Modified To Produce Spider Toxin
Researchers from the University of Maryland in the United States and the IRSS research institute in Burkina Faso genetically enhanced a fungus called Metarhizium pingshaense so it produces spider toxin.
The fungus naturally infects Anopheles mosquitoes that spread malaria. Researchers said the fungus is very malleable, it can be genetically engineered very easily.
Genetic instructions were added to the fungus so it would start making toxin once inside a mosquito. The researchers used a toxin found in the venom of a species of the funnel-web spider in Australia.
"A spider uses its fangs to pierce the skin of insects and inject toxins, we replaced the fangs of spider with Metarhizium," study researcher Raymond St. Leger, from the University of Maryland, said.
Testing The Fungus In Controlled Real-World Setting
Laboratory tests showed the genetically modified fungus kills quicker. The researchers then proceeded to test the fungus in a controlled real-world setting.
They set up a 6,550 square foot fake village called the MosquitoSphere complete with plants, huts, food and water sources for the mosquitoes in Burkina Faso. The village was also enclosed in a double layer of mosquito net to prevent the insects from escaping.
The set-up allowed the researchers to test the fungus in real-world conditions without risking its release into the wild.
Fungus Highly Fatal For Mosquitoes
The researchers mixed the fungal spored with sesame oil and wiped these on to black cotton sheets. The mosquitoes would be exposed to the fungus once they land on these sheets.
In the trial that started with 1,500 mosquitoes, researchers found that the number of mosquitoes increased when they were left alone. However, once they were exposed to the spider-toxin fungus, only 13 of these insects were left after 45 days.
This means that the fungus could wipe out 99 percent of the mosquito population in just a month and a half.
"Deployment of transgenic Metarhiziumagainst mosquitoes could (subject to appropriate registration) be rapid, with products that could synergistically integrate with existing chemical control strategies to avert insecticide resistance," St. Leger and colleagues wrote.
The results of the trial were published in the journal Science.