“Good” bacteria block malaria

Mosquitoes are a major problem around the world, not just because they're annoying, but because they spread deadly malaria which kills over a million people worldwide every year, mostly children in Africa.

This week, researchers at Johns Hopkins Bloomberg School of Public Health in the States have made an important discovery that could pave the way for new ways to tackle these pesky insects. Their work is published in the latest edition of PloS Pathogens.

The researchers focused on bacteria found in the gut of Anopheles gambiae mosquitoes, and discovered that the bacteria help to prevent the mosquitoes from becoming infected with the parasite that causes malaria. When mosquitoes were treated with antibiotics to kill their gut bugs, they became much more susceptible to infection with the malaria parasite. The team also found that infection with the bacteria shortened the mosquito's lifespan.

This is good news because it takes about two weeks for the malaria parasite to complete its life cycle within a mosquito host, so if the mossies are dying earlier, as well as being more resistant to infection with the parasite, it means they're less likely to pass on malaria.

The researchers think that the stimulation of the mosquito's immune system caused by the bacteria also helps to block infection by Plasmodium falciparum, the malaria parasite.

Lead author George Dimopoulos suggests that deliberately introducing the bacteria to wild populations of mosquitoes could be a potential way to control malaria infections.  He and his team are currently trying to identify which strains of bacteria trigger the strongest mosquito immune defense against the malaria parasite.