War against mosquitoes, episode two

The new preparation is based on the protein produced by bacteria, the crystals of which the researchers have learned not only to obtain in required quantities, but also to separate from everything redundant, first of all – from bacteria’s spores.

Elvira Sokolova, manager of the work, who has been dealing with mosquitoes, midges, gnat and other dipterous bloodsucking insects for years, since the time of Ph.D. thesis, says the following in response to the question about advantages of this preparation over the known ones.

“At present, three main types of preparations are used to fight against bloodsucking mosquitoes. Historically, the first and most dangerous type – are chemicals based on chlorine- and organophosphorus compounds, as well as the pyrethroid group. It is no need to say that all of them, particularly the former – are close “relatives” to chemical weapons and are very harmful, besides, they act extremely non-selectively. An alternative, the most contemporary variant is specific viruses affecting only mosquitoes. In principle, these preparations are very good, but they are extremely complicated in manufacturing and, therefore, exceptionally expensive. And, finally, bacterial preparations come in, including our “Larviol”.

The active principle of this preparation – is a special protein, which is excreted by some Bacillus thuringiensis bacteria in the course of their lifecycle. The bacteria produce the protein in the form of crystals, they do it not for the special purpose to provide people with means to exterminate mosquitoes, but simply as a product of life. However, when investigating surprising metabolite, it has turned out that there are creatures for whom such crystals are a very strong intestinal poison. The creatures are bloodsucking mosquitoes’ larvae. As for the rest of water bodies’ inhabitants, more presicely – aquatic life, the protein is absolutely innocuous. Therefore, the solution seemed evident: first, it was needed to let bacteria live properly until they accumulate sufficient amount of required crystals, then to destroy bacteria walls, i.e., to grind them and to educe target crystal protein. In a general way, the scientist act essentially like that– for the first-generation preparations manufacturing.

However, this method has an enormous drawback. On top of proper toxin, the finest bacteria spores get into the preparation, and it is impossible to get rid of them, so bacteria begin to reproduce uncontrollably in the water body, but this is absolutely not needed. This is the drawback we have managed to overcome in a rather non-trivial way. Through long selection we have raised a special clone of bacteria, which propagate themselves without spores at all – in a vegetative way. And we have learned to reproduce the clone.”

The researchers’ effort resulted in this preparation, which we authors have naturally patented and demonstrated it at the latest Biotechnology-2006 exhibition (Moscow). “It is necessary to fight against mosquitoes everywhere and every time, continues Elvira Sokolova. Mosquitoes are not simply vexatious annoyance but a health-threatening factor. Mosquitoes transmit diseases not only in tropical countries, but in Russia as well, for example, the West Nile encephalitis virus, epidemic of which has recently caused death to people in Volgograd. Environmentally friendly anti-mosquito preparation is indeed necessary. Now, it is available. A lot of people believe that mosquito larvae are a habitual feed for fish, and therefore, we must not fight against mosquitoes. But it should be noted that only aquarium fish can be fed with mosquito larvae. In wild nature, bloodsucking mosquito larvae are not the main feed of fish and they most often live in shallow temporary water bodies, simply speaking – puddles.”

The Russian researchers have developed a preparation that meets any sanitary and fish industry regulations, and the World Health Organization recommends to apply it. The only thing to do is to produce it in the quantities so that it would suffice for everyone. But this is the issue of investments – because the method is already available thanks to work by Elvira Sokolova and her colleagues.