Biologists have found a means of protecting people from «zombie parasite» cats

© AP Photo / dpa Julian StratenschulteКот watching the mouseBiologists have found a means of protecting people from «zombie parasite» cats© AP Photo / dpa Julian Stratenschulte

. Toxoplasma gondii, a parasite cats can change the behavior of humans and mice can live in humans without the enzyme, CPL, contained in his «gastric juice», and blocking its synthesis protects people from infection, says the article, published in the journal Nature Microbiology.

«We have several ways to suppress the acute stage of toxoplasmosis, and the immune system generally makes the infection spread much. On the other hand, when the parasite «pupate» and the disease becomes chronic in people with suppressed immunity, and infections of the eye have a very big problem,» says Vern Carruthers (Vern Carruthers) at the University of Michigan in Ann arbor (USA).

Toxoplasma gondii (Toxoplasma gondii) is an intracellular parasite, normally found in the intestine of domestic cats. Today, according to the American CDC, more than 60 million people in the US are infected with Toxoplasma. The prevalence of this pathogen among Pets and their owners forced scientists to draw attention to it in recent years.

It turned out that Toxoplasma gondii is able to change the behavior of the host, causing irreversible changes in the brain. They make mice «fearless» at the sight and smell of cats and people prone to suicide and irrational behavior, and inexplicable fits of rage. In addition, the penetration of Toxoplasma in pregnant woman’s body can cause serious defects in fetus and lead to miscarriage.

Carruthers and his colleagues have figured out how physicians can prevent toxoplasmosis infection and get rid of the already infected people, analyzing the entire life cycle of Toxoplasma gondii and finding the mechanisms that help it survive in «okulina» state inside the cells of humans and animals.

To reveal the mystery, scientists have raised several mice, infected them with Toxoplasma and saw how the genes of the parasite during the transition from acute to chronic phase infection.

As it turned out, the most changed genes, and proteins related to the work of so-called lysosome vacuole of Toxoplasma – a discrete region of the cell, which plays the role of a «stomach» of a single-celled parasite. Inside it, according to Carruthers, Toxoplasma gondii converts and burns all the protein waste arising within the cell or taken in from the external environment.

Disabling the genes associated with the «stomach», the researchers again infected the mice and watched what changed in the behavior of the parasite. Thus they were able to estimate gene CPL, one of the two main enzymes of the vacuoles, the molecules of which turned out to be critical for survival of Toxoplasma in the transition to the chronic form.

Blocking the gene responsible for the synthesis of this protein led to the fact that the number of «oculesics» cells toxoplasmosis is decreased to 100-200. The parasite began worse to penetrate into the brain and other important tissues of the mice, and the surviving cells of Toxoplasma was almost completely filled with «junk» and couldn’t reproduce.

Accordingly, drugs that can suppress the work of protein CPL and related genes and thus to penetrate into the brain, can be an effective cure for people and Pets from toxoplasmosis.

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