UCR Researchers Report Progress Controlling Mosquitoes With Bacteria

RIVERSIDE, Calif. – Researchers at UC Riverside have identified a neurotoxin that isn’t harmful to any living thing except Anopheles mosquitoes. They plan to use it in developing a bacteria-based Anopheles insecticide. 

About 30 years ago, scientists identified a strain of bacteria that kills Anopheles. Since the bacteria’s method of attack was not understood, it couldn’t be replicated or used as an alternative to chemical insecticides – until now. 

It took the team, led by Sarjeet Gill, a professor of molecular, cell and systems biology at UC Riverside, 10 years to achieve a breakthrough in understanding the bacteria. Gill attributes the success to modern gene sequencing techniques. The team hit the bacteria with radiation, creating mutant bacterial strains that could not produce the toxin. By comparing the nontoxic strain to the one that kills Anopheles, they found proteins in the bacteria that are the keys to toxin production. The work is detailed in a paper published in Nature Communications. 

“Identifying the mechanisms by which the bacteria targets Anopheles has not been easy,” Gill said. “We were excited not only to find the neurotoxin, called PMP1, but also several proteins that likely protect PMP1 as it’s being absorbed in the mosquito’s gut.”

Members of Gill’s team include postdoctoral scholars Estefania Contreras, Jianwu Chen, Harpal Dhillon and Nadia Qureshi, as well as graduate students Swati Chawla from UC Riverside, Geoffrey Masuyer and Pål Stenmark from Stockholm University and Han Lim Lee from the Institute for Medical Research in Malaysia. Their work was funded by the U.S. National Institutes of Health.