Anthrax (disease)
Anthrax Bacteria
Anthrax is an infectious disease caused by acute bacterium Bacillus anthracis. It is a anthropozoonosis, that is to say, a condition that affects both animals than humans.
Bacillus anthracis is a biological weapon potential since the end of the Second World War and was specifically mediated following the attacks of September 11, 2001.
History
In 1850, the Pierre Rayer said that Davaine associated with his research, has seen little threadlike body in the blood of sheep with coal There is no evidence or Delete Davaine is suspected in the officer corps of the disease In 1855, the German Aloys Pollender (who claimed he made his discovery as 1849) also described the corpuscles in the blood of animals infected with anthrax, note the appearance of the bacteria particles and, unlike Davaine conjecture that they are the cause of the disease In 1863, Davaine made the anthrax further study, now considered the first evidence of microbial disease transmissible to humans In 1876 Robert Koch discovered the ability of the anthrax bacterium to form spores, which can make it very tough.
In May 1881, at Pouilly-Le-Fort, near Melun, Shepherd makes a famous experiment in vaccination against anthrax in 50 sheep. (In this experiment, including the extent to which one can accuse Pastor of misappropriating an idea of Henry Toussaint") The Pasteur Institute has always strains of Bacillus anthracis of different virulence.
The existence of anthrax toxin was demonstrated for the first time in 1955
Description of the germ
Secondary structure of anthrax toxin is in Greek key pattern.
Bacillus anthracis is a bacterium gram positive, the bacterium is stationary (has no flagellum), which distinguishes it from other bacilli that are mobile, the bacterium is sporulating and type respiratory aerobic / anaerobic optional. The spores of anthrax are highly resistant. They germinate into a vegetative form when they are in environments such as blood or tissue, men or animals, rich in amino acids in nucleotide and glucose. Despite their high resistance, spores do not occur, however they can survive for decades in soil. There is a problem of destruction of Bacillus anthracis by the resistance of spores to drought, heat, UV ultraviolet, the gamma rays and many substances disinfectant. Bacillus anthracis possesses two virulence factors:
- First, the capsule allows it to escape phagocytosis.
- Then there are two toxins composed of three proteins distinct (the antigen protector, edema factor and lethal factor). When the first two proteins are associated, they form the toxin œdématogène whereas when the antigen is associated with protective lethal factor is formed of the lethal toxin. This directly affects the virulence of the bacterium, which suffers a disability, the virulence is reduced by a factor of 1 000.