Biological warfare against malaria

Two recent discoveries indicate a possible new way to fight malaria, a disease caused by protozoans parasites of the genus Plasmodium, especially Plasmodium falciparum.

Researchers of the John Hopkins University and the Malaria Institute of Macha, Zambia, observed that a bacterium belonging to the genus Enterobacter, which lives in the intestine of animals, can block the plasmodium's development.

In particular, they captured Anopheles mosquitoes and analyzed their bacterical flora, discovering that the presence of Enterobacter was correlated to the absence of the plasmodium or to less aggressive parasites. The bacterium produces free radicals that damage the cells with a not fully understood mechanism, and it could be used to counteract the diffusion of the malaria for example placing it into some bites of sugar on which they feed.



Another research guided by Raymond St. Leger, professor of entomology of the University of Maryland, studied the possibility of using the fungus Metarhizium anisopliae, which attacks Anopheles mosquitoes, to fight the plasmodium.

It is possible to insert in its genome genes for a human antibody or a toxin produced by a scorpion, with techniques of genetic engineering: both cause serious damages to the parasite. During the research three gropus of mosquitoes infected by the parasite has been compared. The first infected also by the transgenic fungus, the second by the unmodified strain, and the third without the fungus. The parasite has been found in the 25 % of the first group mosquitoes, the 87 % of the second and the 94 % of the third.

The main benefit of the use of the transgenic fungus is that it attacks selectively the parasite allowing to fight it even in mosquitoes infected for a long time, while it hasn't been possible in previous attempts to fight the plasmodium with fungal infection, since its effectivness was limited exposed to the fungus shortly after the infection of the parasite.