Making Friends With a Malarial Enemy

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The proverb “the enemy of my enemy is my friend” is not only true in politics, it can also be said in the microbial world.

A group of microbes – fungi – have long been an enemy to our enemies. Fungi are yeasts and molds that can produce antibiotics that destroy or inhibit the growth of bacterial cells.

But that's not all they do. A new report shows fungi can also fight a deadly parasitic disease – malaria. This tropical disease is caused by single-celled parasites called plasmodium, of which four species are primarily responsible for making people sick.

The parasite is carried by mosquitos to a vertebrate host, which can be humans, monkeys or even reptiles.

Scientists are attacking the parasite by targeting it in the mosquito. And they're doing so with a fungus called Metarhizium anisopliae or M. anisopliae.

Scientists are experimenting with genetically altered forms of the fungus. These altered M. anisopliae can produce chemicals that identify the parasite in the mosquito's blood and then block the parasite from entering the insect's salivary glands. This way the parasite does not get transferred when an infected mosquito bites a host.

If M. anisopliae proves effective, the plan is to spray the altered fungus on surfaces like interior walls and bed nets, where mosquitoes land. Once the fungus makes contact with the mosquito, it can penetrate the insect's cuticle or exoskeleton and begin replicating in its blood.

Researchers are engineering this fungus to attack malaria in other ways, too. One is being engineered to produce a protein to clump the malarial parasites together, which inactivates them.

Another produces a toxin that kills the parasites. These three approaches may reduce malarial viability by an astounding seventy to ninety percent.

Considering malaria infects over three hundred million people a year and kills a million, these fungal “friends” could have a major impact.

More Information

Development of Transgenic Fungi That Kill Human Malaria Parasites in Mosquitoes
Weiguo Fang, Joel Vega-Rodríguez, Anil K. Ghosh, Marcelo Jacobs-Lorena,
Angray Kang, Raymond J. St. Leger. Research article in prestigious science journal that describes the original experiments. This is a well referenced and illustrated report.
Science 25 February 2011:Vol. 331 no. 6020 pp. 1074-1077. DOI: 10.1126/science.1199115

Malaria
A PubMed Health website that gives a comprehensive view of the malaria parasite, its lifecycle and the disease it causes. There are also extensive links to disease information and treatment and diagnostic approaches among other topics.

World Malaria Report 2010
“The World Malaria Report 2010 summarizes information received from 106 malaria-endemic countries and other sources and updates the analyses presented in the 2009 Report. It highlights continued progress made towards meeting the World Health Assembly (WHA) targets for malaria to be achieved by the end of 2010 and by 2015.”