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Bacteria Play Role in Preventing Spread of Malaria

Malaria is a huge problem around the world, making millions sick and killing hundreds of thousands of children annually. Around the world, scientists are working on vaccines and drugs against malaria. They're promoting the use of bednets and insecticides to kill the mosquitoes that carry the parasite.

But George Dimopoulos from the Johns Hopkins University Malaria Research Institute is trying a novel approach: He wants to cure the mosquito of malaria.

Dimopoulos found that along with the plasmodium parasites that cause malaria, mosquitoes have bacteria in their guts. And that gets the mosquito's immune system working.

"This immune response is controlling the bacteria, but as a byproduct of this immune response, it's also acting against the malaria parasite," Dimopoulos says. "So, when the mosquito has this bacteria in their gut, they are less susceptible to the malaria parasite."

Dimopoulos gave the mosquitoes an antibiotic by suspending the medication in sugar water, which the mosquitoes ate. After the antibiotic killed the bacteria in the mosquitoes' guts, the plasmodium parasites were able to reproduce and thrive inside of them. This made it easier for the mosquitoes to transmit malaria.

Dimopoulos thinks this points to a way of controlling the disease.

"One could think of a bio-control type strategy, by which we would expose mosquitoes to a bacteria species that would have a very strong inhibitory activity to the plasmodium parasite," he says.

Dimopoulos is pursuing this strategy by feeding mosquitoes extra bacteria. He believes this could activate the insect's own immune system to suppress the plasmodium parasites. He has even found a specific kind of bacteria that produces an especially strong immune response to the malaria parasite. Dimopoulos thinks he could start field testing this strategy within the next few years.

"We need to attack this disease from multiple angles with multiple weapons in order to control it," he says. "Actually, I am sure that we would need to use a combination of strategies. This strategy that we are trying to develop could be one of the many weapons against malaria."

Dimopoulos' research is published in the journal PLoS Pathogens.