A recent study published in the journal Science describes how various strains or combinations of strains of the mosquito-infecting fungus Metarhizium anisopliae can block the development of the malarial parasite Plasmodium falciparum in mosquitoes.
M. anisopliae is found throughout the world in soils, and is a disease causing fungus in insects.
According to Dr. Raymond J. St. Leger of the Department of Entomology, University of Maryland, USA – co-author of the study – the genetically engineered fungus “will infect mosquitoes, bore its way through the cuticle, and inject into the mosquito a chemical which will kill malaria, basically curing the mosquito of malaria.”
According to this study, these engineered fungi could be powerful weapons for combating this deadly disease.
One particular combination of M. anisopliae strains was able to reduce the counts of sporozoites – cells produced by the malaria parasites inside the mosquitoes for infecting new hosts – by up to 98 percent.
Such a fungus, which infects mosquitoes upon contact, could be used indoor or outdoor surfaces – as a spray, in a baited trap or in hanging cloth sheets where mosquitoes could land – in the similar manner as we would use a chemical insecticide. Authors suggested that this fungus could help in attenuating the development of resistance against insecticides or it could be used against insecticide-resistant mosquitoes.
According to Dr. St. Leger “mosquitoes are incredibly adaptable. They evolve really fast to outflank everything we put up against them — and become resistant.”
One could use the fungus and the insecticide alternatively, “so the mosquito wouldn’t be exposed to this insecticide year after year to get resistance”, according to Dr. St. Leger.
This fungus could be the silver bullet against this deadly disease affecting the lives of millions of people worldwide every year.
What needs to be seen whether similar strategies could be used to control the spread of other mosquito-bourn diseases, including dengue and chikungunya.
Hemanta K. Sarkar