botulism

Introduction

botulism bŏchˈəlĭzˌəm [key], acute poisoning resulting from ingestion of food containing toxins produced by the bacillus Clostridium botulinum. The bacterium can grow only in an anaerobic atmosphere, such as that found in canned foods. Consequently, botulism is almost always caused by preserved foods that have been improperly processed, usually a product canned imperfectly at home. The toxins are destroyed by boiling canned food for 30 min at 176℉ (80℃). Once the toxins (which are impervious to destruction by the enzymes of the gastrointestinal tract) have entered the body, they interfere with the transmission of nerve impulses, causing disturbances in vision, speech, and swallowing, and ultimately paralysis of the respiratory muscles, leading to suffocation. Symptoms of the disease appear about 18 to 36 hr after ingestion of toxins. Botulinus antiserum is given to persons who have been exposed to contaminated food before they develop symptoms of the disease and is given to diagnosed cases of the disease as soon as possible. Developments in early detection have reduced the mortality rate from 65% to 10%.

See food poisoning.

Medicinal Use of Botulin Toxin

In a technique pioneered by Alan B. Scott, an ophthalmologist, and Edward Schantz, a biochemist, in the late 1970s, botulin toxin has been purified and used in the treatment of debilitating muscle spasms caused by the excessive firing of certain nerves. The treatment utilizes the same process that paralyzes the muscles in botulism poisoning. Injected in tiny amounts into the affected tissue, the botulin blocks the release of acetylcholine, a neurotransmitter that controls muscle contraction, and temporarily relieves the spasms. Botulin was approved by the Food and Drug Administration in 1989 for treatment of blepharospasm (uncontrolled rapid blinking) and strabismus (crossed eyes). The toxin is also injected to treat other conditions, such as neck muscle spasms, and to provide short-term (three to four months) cosmetic treatment of facial wrinkles.

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