U.S. researchers have identified 11 genes that malaria parasites use to defend themselves against standard treatments, a finding that could prolong the life of current drugs or help find better ones.

A team at Harvard University and the Broad Institute in Boston used advanced gene-hunting technology to search the genetic code of the malaria parasite Plasmodium falciparum.

They found 10 previously undiscovered genes that help the mosquito-borne parasite quickly develop resistance to malaria treatments and confirmed the role of another.

Adding extra copies of just one of these genes, PF10_0355, to a parasite still vulnerable to malaria drugs made it more resistant to three standard treatments.

"Identification of mutations associated with drug resistance helps us understand how the parasite evades the effects of the drug," said Sarah Volkman of Harvard, who helped write the paper published on Thursday in the Public Library of Science journal PLoS Genetics.

"Once we understand the processes used by the parasite to avoid the effects of the antimalarial treatment, scientists can develop new drugs that circumvent the strategies employed by the drug-resistant malaria parasite," Volkman said in a statement.

Scientists are increasingly looking to manipulate genes as a way to control the spread of malaria, which affects more than 240 million people every year, and kills around 850,000 annually -- many of them children in Africa.

Researchers said on Wednesday they have found a way of genetically manipulating large populations of mosquitoes that could eventually dramatically reduce the spread of the deadly disease.

Reducing the toll of malaria is a major challenge because of the parasite's talent for swiftly developing resistance to multiple drugs.

To understand how they do it, teams at Harvard and Broad analyzed the genetic code of 57 parasites from three continents. They also measured the parasites' responses to 13 antimalarial drugs.

The scientists looked specifically for areas of the genome that were evolving rapidly, searching for variants linked with drug resistance. They found 11 genes.

Tests on one of these -- PF10_0355 -- showed that adding extra copies of the gene from a resistant parasite to one still sensitive to drugs made the sensitive one more drug resistant.

That suggests the gene is playing a role in making the parasite drug-resistant, said Daria Van Tyne, one of the study's authors.

The team said the study may help prolong existing drugs and will help in the search for drugs that are more effective at defeating the parasite's genetic defenses.