Bacillus Anthracis Essay, Research Paper
Bacillus Anthracis
Robert Koch discovered Bacillus Anthracis, the bacterium for the deadly disease, Anthrax, in 1877. Robert Koch grew the bacterium into a pure culture, demonstrated its ability to form endospores, and produced experimental Anthrax by injecting it into animals. Bacillus Anthracis was the first bacterium shown to be the cause of a disease. Bacillus Anthracis is a very large, gram positive sporeforming rod. The organism is cultivated on ordinary nutrient medium and grows best aerobically, but can also multiply under anaerobic conditions. The disease, Anthrax, is very deadly but it is rare. The risk of infection is 1/100,000. The disease is acquired when spores from a contaminated animal carcass inoculate an open wound. Then, the spores germinate and invade the blood stream, leading to death within 48 hours. Bacillus Anthracis is classified as a harmful, pathogenic bacterium. There is a vaccine for Anthrax in humans, but it produces no significant immunity. The vaccine is given primarily to people who work with livestock or in other businesses where workers must handle animal carcasses. The livestock version of the vaccine is very effective, however. The vaccine for both animals and humans is composed of sublethal amounts of toxin that induce formation of protective antibody. Frequent boosters are necessary to maintain resistance to Anthrax. Bacillus Anthracis spores also may live in soil for years. The only way to destroy the spores is by steam sterilization or burning. There has been no evidence of person to person transmission of the disease, though Anthrax was a subject of great concern for the military in the Gulf War. Many believed that the Iraqi armies held canisters of the Anthrax bacterium that they could use against their enemies. The largest reported outbreak of Anthrax was in 1956 in Scotland, where 70 people died of the disease in one week due to exposure to infected sheep in a farming village.