Every year, more than 200 million people are affected by malaria and 50 to 100 million new dengue infections occur. Now, a group of scientists from Johns Hopkins University may have found a novel way of curbing both diseases: by "vaccinating" mosquitos against the parasite that causes malaria and the virus that causes dengue. The researchers are using the bacteria Chromobacterium, which prevents the pathogens from effectively invading and colonizing mosquito guts.
As Science magazine reported last week:
Like humans and most other animals, mosquitoes are stuffed with microbes that live on and inside of them--their microbiome. When studying the microbes that make mosquitoes their home, researchers came across one called Chromobacterium sp. (Csp_P). They already knew that Csp_P's close relatives were capable of producing powerful antibiotics, and they wondered if Csp_P might share the same talent.
In another experiment, done with mosquitoes that weren't pretreated with antibiotics, Csp_P-fed mosquitoes were given blood containing the dengue virus and Plasmodium falciparum, a single-celled parasite that causes the most deadly type of malaria. Although a large number of the mosquitoes died within a few days of being infected by the Chromobacterium, the malaria and dengue pathogens were far less successful at infecting the mosquitoes that did survive, the team reports today in PLOS Pathogens. That's good news: If the mosquito isn't infected by the disease-causing germs, it is less likely to be able to transmit the pathogens to humans.
The bacteria also inhibited growth of Plasmodium and dengue in lab cultures, indicating that Csp_P is producing compounds that are toxic to both pests. One possible application of these toxins is to develop treatment drugs for people already infected with malaria or dengue. Real-world applications of this research are many years in the future, but it hints at a whole new way of dealing with otherwise intractable diseases.
Previously: Close encounters: How we're rubbing up against pathogen-packing pests, Closing the net on malaria and Fighting fire with fire? Using bacteria to inhibit the spread of dengue
Photo by Sanofi Pasteur