Sunday, October 26, 2014
Clash of infectious agents: bacteria helps prevent malaria and dengue infection
A team of scientists from Johns Hopkins University has uncovered a novel way to prevent malaria and dengue: by introducing microbial agents of the genus Chromobacterium (Csp_P) to the guts of mosquito vectors, scientists were able to induce immunity to both Plasmodium and dengue virus. Successful Csp_P colonization in Anopheles and Aedes (the vectors for malaria and dengue, respectively) activates a mosquito immune response that helps prevent the establishment of viral and parasitic infection. In vitro tests also suggest Csp_P may directly interact with invasive agents and produce anti-pathogenic molecules that inhibit pathogen survival in the mosquito's gut. This observation has a further implication: the toxins Csp_P uses to kill pathogens in mosquitoes can be studied to help produce drugs to treat malaria and dengue in humans.
Csp_P has also been shown to have entomopathogenic activity, as a significant portion of mosquitoes colonized by Chromobacterium during testing died shortly after initial Csp_P ingestion. All of this data suggest the possibility of using Csp_P as an efficacious malaria and dengue vector control measure: by lacing sugar-baited traps (currently used to spread insecticide) with Csp_P, public health officials can both kill most mosquitoes that feed from the traps and prevent any surviving mosquitoes from spreading malaria and dengue.
In is important to note, however, that since Csp_P appears to be such a toxic agent, it may exhibit damaging effects on human cells in addition to invasive organisms. The research on Csp_P remains in its infancy, so further testing will show whether or not it can be used to safely control disease.