Researchers at Johns Hopkins Malaria Research Institute said their breakthrough could help prevent mosquitoes from transmitting malaria to humans.
Malaria kills over 800,000 people worldwide every year, most of them are children.
In the new study, published in the journal Proceedings of the National Academy of Sciences, the researchers modified the bacterium, called Pantoea agglomerans, to secrete proteins that are toxic to the malaria parasite, but not harmful to the mosquito or humans.
The bacterium is commonly found in the mosquito's midgut.
It was found that the modified bacteria were 98 per cent effective in reducing the malaria parasite burden in the insects, the researchers said.
"In the past, we worked to genetically modify mosquitoes to resist malaria, but genetic modification of bacteria is a simpler approach," Prof Marcelo Jacobs-Lorena, who led the research, said in a statement.
"The ultimate goal is to completely prevent the mosquito from spreading the malaria parasite to people," he noted.
Jacobs-Lorena and his team found that the engineered P. agglomerans strains inhibited development of the deadliest human malaria parasite "Plasmodium falciparum" and rodent malaria parasite "Plasmodium berghei" by up to 98 per cent within the mosquito. The proportion of mosquitoes carrying parasites (prevalence) decreased by up to 84 per cent.
"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," added Jacobs-Lorena.
