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German and Israeli scientists have developed a means to prevent malaria

The bacterium that develops a toxin is scattered in the swamps where mosquitoes breed, Israelis are partners in its discovery and the development of the drug

A mosquito bite. Photo: shutterstock
A mosquito bite. Photo: shutterstock

continues to drop spaces around the world. With global warming, the Anopheles mosquitoes that carry the parasites are spreading to large areas where they were not previously, thus expanding the risk areas for malaria infection.

The war against malaria is mainly conducted on three levels:

  • Protection against the mosquitoes that spread the disease by means of nets, nets, materials that repel the mosquitoes and more. At the same time, the destruction of mosquitoes is carried out in breeding centers - puddles and the like.
  • Treatment of the parasites that cause the disease, even though it is one of the most common diseases in the world, until today no reliable way to cure it has been found.
  • There are drugs to prevent the disease, but in the competition between the drug manufacturers and the parasites, the parasites win by developing resistance to the drugs.

The treatment of the spreaders of the disease, the mosquitoes, is progressing more and more. Today, until recently, it was customary to spray puddles and breeding grounds for the mosquitoes with chemicals, such as D.D.T. and its substitutes that harm mosquito larvae. These substances destroy not only the mosquito larvae but all the animals in the environment.

One of the innovative and sustainable ways of treatment is by dispersing bacteria that produces a toxin. According to the name of the bacterium Bacillus thuringiensis israelensis (Bti) (hereinafter: BTI) it can be understood that Israelis are involved in its development. The treatment with the bacteria is effective and does not harm the environment, except that the toxin breaks down quickly, therefore in each growth cycle of the mosquito larvae it is necessary to renew the population of the bacteria, which increases the cost of the treatment.

Researchers from German research institutes Department of System Ecotoxicology at the Helmholtz Center for Environmental Research publish in the Journal of Vector Ecology the possibility of treatment by a variety of crustacean species found in freshwater puddles and basins. It turns out that the tiny crustaceans prey on the mosquito larvae. According to the researchers "for the first time we showed that a population of cancer cells is more effective than BTI. in the treatment of mosquito larvae".

For the purpose of the study, the researchers populated several puddles with mosquito larvae. In each puddle there was a different amount and different species of crustaceans, in each test the numbers of mosquito larvae were measured and how many of them reached maturity. After 21 days (roughly the time it takes for mosquitoes to develop from larvae to adults), the researchers added B.T.I. to test the effect on cancer. It turns out that the population of mosquito larvae in the treated puddles decreased by dozens of meters, also, it turned out that in the puddles the sensitivity of the mosquito larvae to the BTI toxin increased tenfold. It also turned out that the effect of the B.T.I. It was hardly noticeable in the puddles where there was a more diverse population of crustaceans, since the number of mosquito larvae was minimal.

 

The study was conducted in Leipzig, Germany and the mosquitoes were Culex pipiens (Culex mosquitoes do not carry the fever parasites). To test the method on mosquitoes that carry the parasites (Anopheles), members of the research team tested the method in Kenya in areas where malaria-carrying mosquitoes grow, in collaboration with the Center of Insect Physiology and Ecology in Kenya, and the results were positive.

 

According to the leader of the study: "Treatment of mosquitoes with chemicals will always be for a limited time and will cause harm to the environment. With the help of the crustaceans it is possible to treat the mosquito populations and even use the treated water for drinking. The method can be applied in the developing world because in all the lakes the crustaceans can be collected with a net and dispersed in any puddle or breeding centers of the mosquitoes."

 

There is an Israeli side (additional to the development of the BTI): Prof. Leon Blaustein, from the Department of Ecology at the University of Haifa, said: "This work adds to the accumulated information that shows that crustaceans are competitors for mosquito larvae and as such reduce their population, improving the diversity of the fauna in the territories Wetlands and thus reduce the spread of malaria." and adds: "The integration of B.T.I. And Sartanaim enables friendly management of the humid environment without harming the environment."

More on the subject on the science website:

10 תגובות

  1. Combinations like these are welcome in the field of malaria eradication, but what about the combination of the common gambosia that has proven itself quite a few times in Israel and around the world?
    In addition, you have a mistake in the picture. The mosquito is of the genus Aedes and not Anopheles.

  2. In this case, as written in the response, it is really old news.
    I read about the bacteria 20-30 years ago, but it's still interesting.

  3. "According to the name of the bacterium... it can be understood that Israelis are involved in its development"
    Well, not in its development but in its discovery.
    At the end of the seventies, when I was a biology student at Ben Gurion University, my insect lecturer, the late Prof. Yoel Margalit, discovered a bacterium capable of harming mosquitoes (a toxin crystal was formed in the bacterium that destroys the stomach of the mosquito larvae. The bacterium was named: the Israeli bacillus and also in Latin It was written like this) following the discovery of many larval carcasses in a number of water bodies in the Negev (he was able to understand that there is something in the water that causes their death and managed to isolate the bacteria). He received exciting letters from all over the world that his discovery would solve a serious problem. He was angry at the State of Israel for not being willing to invest in the production of the bacteria and the university sold the "patent" to another country and they are making a lot of money from the worldwide production of the bacteria. The problem is that the bacteria is not effective in all types of water bodies.
    More on that:
    http://bioteach.snunit.k12.il/upload/.html05/madbirim.html
    Partial quote:
    "A significant breakthrough in research dealing with the search for effective ways to control mosquitoes was the discovery of Prof. Yoel Margalit. In 1976, he identified a bacterium in the bed of Nahal Hashur in the Negev that was unknown to science until then and which is capable of harming mosquitoes. The name given to the bacterium is "the Israeli bacillus" - (Bti). Bacillus thuringiensis subsp. israelensis”

    And words in memory of Prof. Yoel Margalit
    http://israel.agrisupportonline.com/news/csv/csvread.pl?show=1658&mytemplate=tp2

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