Monday, February 28, 2011

Metarhizium anisopliae as Eco-friendly Antimalarial Biopesticide

Malaria is one of the major public health problem for Nepal, indeed all developing countries are facing the problem. Although epidemics of malaria has been reduced, emergence of drug resistant Plasmodium spp (causative agent of malaria), poor sanitation, agricultural dependency etc. still making malaria as frightening.

Living in the Terai region of Nepal was avoided due to malaria. This is the fact of just 60-70 years ago. During Rana rule in Nepal, prisoners were sent to this Terai area as punishment, where malaria was a big threat. After the discovery of anti-malarial drugs, deforestation and people's migration began and the Terai gradually overcrowded and become Nepal's dense populated area. I remember, whole houses were sprayed by DDT to get rid from the diseases transmitted by mosquito. But DDT exhibited serious environmental and public health hazards. And neither, malaria could be eliminated.

The finding (gift of science and research ?) from the University of Maryland may be helpful to combat malaria and mosquito related diseases in Eco-friendly and biological way. A fungus Metarhizium anisopliae, which is a plants symbiont protecting plants from insect, infects mosquito and some other insects and attenuates then kills. This fungus has been genetically modified (GM) and have very narrow host range e.g., only infect harmful insects. Also, this GM fungus express SM1 and scorpion proteins, toxic to Plasmodium sporozoites in mosquito that enhance the rate of killing in short time period. This fungus easily invade and infect the mosquito through the surface like if contacted to cuticle; unlike bacterial and viral infection. So, like DDT, spore of this fungus can be sprayed in bed net, house; so that it would be easily contact with mosquito and to eliminate Plasmodium spp. And, it could infect larvae of mosquito, hence meta-acid and hazardous chemicals can be replaced by the fungal spore in ditches and stagnant water pool.

However, whether this genetic engineered fungus can survive freely in environment or work significantly? Or might it create bad impact in ecology? Or will it be available easily for poor countries to use? What happens if it infect honey bee and other beneficial insects ? We have to wait.

Reference: Fang et al., Science (25 February, 2011), 331; 1074-1077

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