Genetically engineered bacteria prevent mosquitoes from transmitting malaria

WASHINGTON, July 16 (Xinhua) -- U.S. researchers have genetically modified a bacterium commonly found in the mosquito's midgut and found that the parasite causing malaria in people does not survive in mosquitoes carrying the modified bacterium, according to a report published Monday in the Proceedings of the National Academy of Sciences.

The bacterium, Pantoea agglomerans, was modified to secrete proteins toxic to the malaria parasite, but the toxins do not harm the mosquito or humans. The modified bacteria were 98 percent effective in reducing the malaria parasite burden in mosquitoes, said the report.

"In the past, we worked to genetically modify the mosquito to resist malaria, but genetic modification of bacteria is a simpler approach," said Marcelo Jacobs-Lorena, senior author of the study and a professor with Johns Hopkins University's Bloomberg School of Public Health. "The ultimate goal is to completely prevent the mosquito from spreading the malaria parasite to people."

With the study, the researchers found that the engineered Pantoea agglomerans strains inhibited development of the deadliest human malaria parasite Plasmodium falciparum and rodent malaria parasite Plasmodium berghei by up to 98 percent within the mosquito. The proportion of mosquitoes carrying parasites ( prevalence) decreased by up to 84 percent.

"We demonstrate the use of an engineered symbiotic bacterium 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," said Jacobs-Lorena.

Malaria kills more than 800,000 people worldwide each year, many of whom are children.