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Clostridium tetani with characteristic 'tennis racket' appearance.
| Scientific classification
| C. tetani
Clostridium tetani is a rod-shaped, anaerobic bacterium of the genus Clostridium. Like other Clostridium species, it is Gram-positive, and its appearance on a gram stain resembles tennis rackets or drumsticks. C. tetani is found as spores in soil or as parasites in the gastrointestinal tract of animals. C. tetani produces a potent biological toxin, tetanospasmin, and is the causative agent of tetanus, a disease characterized by painful muscular spasms that can lead to respiratory failure and, in up to 40% of cases, death. Contents[hide] * 1 History * 2 Characteristics * 3 Vaccination * 4 Toxicity * 4.1 Toxin Action * 5 Treatment * 6 References * 6.1 Further reading * 7 External links
|  History
Tetanus was well known to ancient people, who recognized the relationship between wounds and fatal muscle spasms. In 1884, Arthur Nicolaier isolated the strychnine-like toxin of tetanus from free-living, anaerobic soil bacteria. The etiology of the disease was further elucidated in 1884 by Antonio Carle and Giorgio Rattone, who demonstrated the transmissibility of tetanus for the first time. They produced tetanus in rabbits by injecting their sciatic nerve with pus from a fatal human tetanus case in that same year. In 1889, C. tetani was isolated from a human victim, by Kitasato Shibasaburo, who later showed that the organism could produce disease when injected into animals, and that the toxin could be neutralized by specific antibodies. In 1897, Edmond Nocard showed that tetanus antitoxin induced passive immunity in humans, and could be used for prophylaxis and treatment. Tetanus toxoid vaccine was developed by P. Descombey in 1924, and was widely used to prevent tetanus induced by battle wounds during World War II.  Characteristics
C. tetani is a rod-shaped, obligate anaerobe which stains Gram positive in fresh cultures; established cultures may stain Gram negative. During vegetative growth, the organism cannot survive in the presence of oxygen, is heat-sensitive and exhibits flagellar motility. As the bacterium matures, it develops a terminal spore, which gives the organism its characteristic appearance. C. tetani spores are extremely hardy as they are resistant to heat and most antiseptics. The spores are distributed widely in manure-treated soils and can also be found on human skin and in contaminated heroin.  Vaccination
Tetanus can be prevented through the use of an effective vaccine, simple or adsorbed Tetanus vaccine, combined Tetanus and Killed Polio vaccine, or the older DTP (diphtheria, tetanus, pertussis) vaccine. Side effects are rare, but if they do occur, include: * Fever
* Pain at the injection site
* Unexplained crying in infants, irritability in older children or adults. Severe reactions are extremely rare and include anaphylaxis, seizures and encephalopathy. These events are thought to occur less if only the tetanus-diphtheria component of the vaccine is given. It is recommended that all infants receive the vaccine at 2, 4, 6, and 15 months of age. A fifth booster dose should be given at 4-6 years of age. After that, it should be given every 10 years. However, if a bite, scratch, or puncture occurs more than five years after the last dose of vaccine, the patients should receive another dose of vaccine.  Toxicity
C. tetani usually enters a host through a wound to the skin and then it replicates. Once an infection is established, C. tetani produces two exotoxins,...
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