Fighting Malaria with Genetically Modified Mosquitoes
According to the WHO, malaria caused 800 million deaths in 2010.
Eradicating the cause is one way to curtail this disease. The most vulnerable stages of Plasmodium (including Plasmodium malariae which is closely related to Plasmodium falciparum and Plasmodium vivax which are responsible for most malarial infections) development occur in the lumen of the mosquito midgut, a compartment shared with symbiotic bacteria. A strategy that uses symbiotic bacteria to deliver antimalaria effector molecules to the midgut lumen, thus rendering host mosquitoes obstinately resistant to malaria infection. The Escherichia coli hemolysin A secretion system was used to promote the secretion of a variety of anti-Plasmodium effector proteins by Pantoea agglomerans, a common mosquito symbiotic bacterium. These engineered P. agglomerans strains inhibited development of the human malaria parasite Plasmodium falciparum and rodent malaria parasite Plasmodium berghei by up to 98%. The use of an engineered symbiotic bacterium has been shown to interfere with the development of P. falciparum in the mosquito. These findings provide the foundation for the use of genetically modified symbiotic bacteria as a powerful tool to combat malaria. (Reported in the July 16, 2012 issue of the Proceedings of the National Academy of Science)