Nearly half the world’s population lives in areas vulnerable to malaria which kills roughly 450,000 people per year, most of them children and pregnant women. Various approaches used to decrease malaria incidences include the control of mosquitos that act as a vector to spread the disease. Progress fighting the disease is threatened as mosquitos develop resistance to chemical insecticides used to control them. There is also great concern about toxic side effects of these chemicals. Biological approaches used in vector control can be effective, as evidenced by successful intervention of parasitic worm transmission in West Africa using the bacterium, Bacillus thuringiensis israelensis (Bti). In its over two-decade use controlling blackflies, no resistance has been observed to Bti, but it is not effective against the certain species of mosquitos.
Prof. Sarjeet Gill and his colleagues at UCR have identified a potent mosquitocidal protein, PMP1, that is active against Anopheles and Aedes mosquitos. This protein was identified from a bacterial strain that has high mosquitocidal activity specifically against Anopholes. PMP1 bears 30 percent chemical similarity to botulinum or tetanus however it has no affect on humans, vertebrates or fish.
Fig. 1 shows the toxicity of PMP1 and inactive PMP1 E209Q mutant to mosquito larvae by injection in a dose–mortality plot.
Fig. 2 shows the percentage of adult mosquitoes and Drosophila flies (percent) stopped flying after 24 hours of injection with PMP1.