Causes and Symptoms (Magill’s Medical Guide, Sixth Edition)
Clostridium botulinum is a bacillus that produces spores. Both bacteria and spores can be found in the intestines of humans and other animals as well as in contaminated soil and water. The spores are highly resistant to heat and can survive boiling and other measures employed to kill bacteria and destroy toxins for safe food preparation. Under appropriate anaerobic conditions (those lacking oxygen), the spores germinate into the toxin-producing vegetative bacilli. The exotoxin is a protein synthesized within the bacteria and released only after the death and lysis (disintegration) of the bacteria. When ingested, the toxin resists the acid and enzymes of the stomach by creating complexes with other bacterial proteins. This allows the toxin to reach the intestines, where it is absorbed into the bloodstream and carried to nerve endings. The toxin is bound and internalized into the presynaptic nerve endings, preventing release of the neurotransmitter acetylcholine. The binding is irreversible, and recovery can occur only after nerve endings regenerate.
Human illness is caused by toxin ingestion or the entry of toxin-producing bacteria into the host. Improper processing of food, especially home canning, can result in the germination of contaminating spores, with subsequent toxin production. Food poisoning occurs when toxin-containing food is ingested, unless it has has been heated sufficiently to denature the protein...
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Treatment and Therapy (Magill’s Medical Guide, Sixth Edition)
The outcome of botulism has improved with the development of critical care and supportive measures. Intubation and mechanical ventilation is vitally important until neuromuscular control of breathing is regained. Specific treatment with botulism antitoxin may be used in severe or progressive cases. Because this antitoxin is of equine origin, however, a high incidence of hypersensitivity reactions (9 to 20 percent) occurs in human patients.
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
In 1820, a German named Justinus Kerner first noted the association between sausage consumption and paralytic disease. The term “botulism” is derived from botulus, the Latin word for “sausage.” Wound botulism was first recognized in 1943. Infant botulism, which is caused by swallowed spores rather than preformed toxin, was first noted in 1976. The most common form of human botulism in the United States, infant botulism can be contracted from exposure to honey, but most cases seem to be related to spores found in soil and dust.
Despite these insights, however, the epidemiology of many botulism cases remains obscure. A diagnostic test more rapid and widely available than the mouse neutralization test, which takes forty-eight hours, is needed. Antitoxin, perhaps from deoxyribonucleic acid (DNA) hybridization technology, would improve therapy over the scarce and dangerous equine product.
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
Brachman, Philip S., and Elias Abrutyn, eds. Bacterial Infections of Humans: Epidemiology and Control. 4th ed. New York: Springer Science and Business Media, 2009.
Mandell, Gerald L., John E. Bennett, and Raphael Dolin, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 7th ed. New York: Churchill Livingstone/Elsevier, 2010.
Pommerville, Jeffery C. Alcamo’s Fundamentals of Microbiology. 9th ed. Sudbury, Mass.: Jones and Bartlett, 2010.
(The entire section is 66 words.)
Botulism (Encyclopedia of Medicine)
Botulism is caused by botulinum toxin, a natural poison produced by certain bacteria in the Clostridium genus. Exposure to the botulinum toxin occurs mostly from eating contaminated food, or in infants, from certain clostridia growing in the intestine. Botulinum toxin blocks motor nerves' ability to release acetylcholine, the neurotransmitter that relays nerve signals to muscles, and flaccid paralysis occurs. As botulism progresses, the muscles that control the airway and breathing fail.
Botulism occurs rarely, but it incites concern because of its high fatality rate. Clinical descriptions of botulism possibly reach as far back in history as ancient Rome and Greece. However, the relationship between contaminated food and botulism wasn't defined until the late 1700s. In 1793 the German physician, Justinius Kerner, deduced that a substance in spoiled sausages, which he called wurstgift (German for sausage poison), caused botulism. The toxin's origin and identity remained elusive until Emile von Ermengem, a Belgian professor, isolated Clostridium botulinum in 1895 and identified it as the poison source.
Three types of botulism have been identified: food-borne, wound, and infant botulism. The main difference between types hinges on the route of exposure to the toxin....
(The entire section is 1944 words.)
Botulism (Encyclopedia of Neurological Disorders)
Botulism is a neuroparalytic disease caused by the potent toxin of the Clostridium botulinum bacterium. There are three main types of botulism: foodborne botulism, infant botulism, and wound botulism.
Botulism was first identified in Wildbad, Germany, in 1793, when six people died after consuming a locally produced blood sausage. In 1829, Jutinius Kerner, a health official, described 230 cases of sausage poisoning. Thereafter, the illness became known as "botulism," which is derived from the Latin "botulus," meaning sausage. In 1897, E. Van Ermengem identified the bacterium and its toxin while investigating an outbreak of the disease among musicians in Elezells, Belgium.
C. botulinum is a spore-forming, anaerobic, grampositive bacilli found globally in soil and honey. The toxin has recently gain notoriety. It is a potential bioterrorism agent, and it is used as a beauty aid to eliminate frown lines.
Clinically, food-borne botulism is dominated by neurological symptoms, including dry mouth, blurred vision and diplopia, caused by the blockade of neuromuscular junctions.
In wound botulism the neurologic findings are similar to the food-borne illness, but the gastrointestinal symptoms are absent. Infants suffering from the intestinal...
(The entire section is 1069 words.)
Botulism (Encyclopedia of Children's Health)
Botulism is an acute, progressive condition caused by botulinum toxin, a natural poison produced by the spore-forming bacteria Clostridium botulinum. Exposure to the botulinum toxin usually occurs from eating contaminated food although, in infants, it may be caused by specific types of clostridia obtained from soil or inhaled spores, causing growth of the bacteria in the infant's intestine. Botulinum toxin is a neurotoxin that blocks the ability of motor nerves to release acetylcholine, the neurotransmitter that relays nerve signals to muscles, a process that may result in unresponsive muscles, a condition known as flaccid paralysis. Breathing may be severely compromised in progressive botulism because of failure of the muscles that control the airway and breathing.
Botulism occurs only rarely, but its high fatality rate makes it a great concern for those in the general public and in the medical community. Clinical descriptions of botulism reach as far back in history as ancient Rome and Greece. However, the relationship between contaminated food and botulism was not defined until the late 1700s. In 1793 the German physician, Justinius Kerner (1786862), deduced that a substance in spoiled sausages, which he called...
(The entire section is 2720 words.)
Botulism (Encyclopedia of Public Health)
Botulism is a rare disease that occurs in four forms: food-borne botulism (the most common form); infant botulism (sometimes associated with honey); an adult form of infant botulism; and wound infection botulism. Botulism is caused by botulinum neurotoxin, which blocks acetylcholine release at neuromuscular junctions, resulting in paralysis. The toxin is produced under anaerobic conditions by Clostridium botulinum, a bacterium found widely in the environment.
In food-borne botulism, the preformed toxin is ingested. There are two main bacterial strains: Group I strains are proteolytic, have spores that are highly resistant to heat, and cannot grow below 10°C. Group II strains are nonproteolytic, are less likely to survive thermal processing or grow in acid or salty products, and grow at refrigeration temperatures. The canning industry has developed retort conditions to prevent the survival of all spores.
Symptoms of food-borne botulism include double vision, inability to speak or swallow, labored breathing, and death. Food-borne botulism can be caused by improperly processed or stored foods, including vegetables, meat, fish, and cheese. The annual incidence of botulism is highest in Russia, Poland, and Hungary with 0.2 to 0.3 cases per 100,000 persons (due to contaminated home-preserved foods); and in the Innuit populations of Canada and Alaska (60 cases per 100,000 persons in northern Quebec), where it is usually associated with toxins in putrefied whale, seal, or fish products.
Symptoms of infant botulism include constipation, weakness, and respiratory arrests, but rarely death.
(SEE ALSO: Food-Borne Diseases)
Austin, J. W., and Dodds, K. L. (2001). "Clostridium botulinum." In Food-borne Disease Handbook, 2nd edition, eds. Y. H. Hui, M. D. Pierson, and J. R. Gorham. New York: Marcel Dekker.
Center for Food Safety and Applied Nutrition. Clostridium botulinum. In Bad Bug Book (Food-borne Pathogenic Microorganisms and Natural Toxins Handbook). Washington, DC: Center for Food Safety and Applied Nutrition U.S. Food and Drug Administration. Available at .
Botulism (Encyclopedia of Food & Culture)
BOTULISM. Botulism is a paralytic illness caused by a nerve toxin produced by the soil bacterium Clostridium botulinum and spread by contaminated food or by infection of a wound. The term comes from the Latin botulus (sausage), but the vehicle in food-borne cases today is usually vegetables or other food improperly canned at home. Commercial canning is almost never implicated, although a notable case in 1971 left one person dead and several others seriously injured. The illness is rare, with only twenty-five to thirty food-borne cases reported annually in the United States.
C. botulinum is a spore-forming bacteria that can lie dormant in the soil for months or years. In a warm, moist, low-oxygen environment, however, the spores can produce vegetative cells that multiply rapidly and secrete a deadly toxin, which attacks the nervous system of the person ingesting contaminated food.
Symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty in swallowing, dry mouth, and muscle weakness. An antitoxin can be used with early diagnosis, but otherwise treatment involves supportive care, sometimes including a ventilator. A severe case can require months of medical and nursing care and may leave the patient with permanent impairments. Botulism is fatal in about 8 percent of cases, usually from respiratory failure.
Thorough washing can remove the spores and proper heating will destroy them. If, however, the food being canned is not washed properly and fails to reach the necessary temperature for the required time, the spores can germinate and produce toxin in the canned goods.
A pH in the acid range will also kill the spores, so acidic foods such as fruit and tomatoes are less likely to be vehicles than low-acid food such as corn, green beans, or asparagus. Canners are often advised to raise the acidity of food by adding an acid source such as lemon juice or citric acid.
To avoid the danger of botulism, home canners of low-acid foods are advised to use a pressure canner instead of the unpressurized, boiling-water-bath systems used previously. A temperature of up to 250°F is needed, which can be reached with pressure canners operated at ten to fifteen pounds per square inch. The time required ranges from twenty to one hundred minutes, depending on the food and the size of the jars. Detailed instructions are available with home canning systems, either from the U.S. Department of Agriculture or from an extension agent.
Industrial quality control makes it highly unlikely that commercially canned food will be contaminated with botulinum toxin. However, consumers should reject any commercial canned goods that appear swollen or bulging and any canned food with a bad smell or flavor.
In recent years, scientists have recognized an infant form of botulism in which infants ingest spores that germinate and produce toxins in the intestines. This appears to be linked mainly to the ingestion of raw honey, so authorities urge parents never to feed raw honey to babies. There is little danger of this variant of the disease after the age of one year.
See also Packaging and Canning, History of; Packaging and Canning, Modern; Safety, Food.
Centers for Disease Control and Prevention. "Botulism." At http://www.cdc.gov/health/botulism.htm.
Silliker, J. H., ed. Microbial Ecology of Foods. Vol. 1. New York: Academic Press, 1980.
U.S. Department of Agriculture. Complete Guide to Home Canning. Washington, D.C., 1994.
Richard L. Lobb
Botulism (World of Microbiology and Immunology)
Botulism is an illness produced by a toxin that is released by the soil bacterium Clostridium botulinum. One type of toxin is also produced by Clostridium baratii. The toxins affect nerves and can produce paralysis. The paralysis can affect the functioning of organs and tissues that are vital to life.
There are three main kinds of botulism. The first is conveyed by food containing the botulism toxin. Contaminated food can produce the illness after being ingested. Growth of the bacteria in the food may occur, but is not necessary for botulism. Just the presence of the toxin is sufficient. Thus, this form of botulism is a food intoxication (as compared with food poisoning, where bacterial growth is necessary). The second way that botulism can be produced is via infection of an open wound with Clostridium botulinum. Growth of the bacteria in the wound leads to the production of the toxin, which can diffuse into the bloodstream. The wound mode of toxin entry is commonly found in intravenous drug abusers. Finally, botulism can occur in young children following the consumption of the organism, typically when hands dirty from outdoor play are put into the mouth.
The latter means of acquiring botulism involves the form of the bacterium known as a spore. A spore is a biologically dormant but environmentally resilient casing around the bacterium's genetic material. The spore form allows the organism to survive through prolonged periods of inhospitable conditions. When conditions improve, such as when a spore in soil is ingested, resuscitation, growth of the bacterium, and toxin production can resume. For example, foodborne botulism is associated with canned foods where the food was not heated sufficiently prior to canning to kill the spores.
Botulism is relatively rare. In the United States, just over 100 cases are reported each year, on average. The number of cases of foodborne and infant botulism has not changed appreciably through the 1990s to the present day. Foodborne cases have tended to involve the improper preparation of home-canned foods.
There are seven known types of botulism toxin, based on their antigenic make-up. These are designated toxins A through G. Of these, only types A, B, E, and F typically cause botulism in humans, although involvement of type C toxin in infants has been reported, and may be particularly associated with the consumption of contaminated honey.
Infant botulism caused by toxin type C may be different from the other types of botulism in that the toxin is produced in the person following the ingestion of living Clostridium botulinum.
The toxins share similarities in their gross structure and in their mechanism of action. The toxins act by binding to the region of nerve cells that is involved in the release of a chemical known as a neurotransmitter. Neurotransmitters travel across the gap (synapse) separating neurons (nerve cells) and are essential to the continued propagation of a neural impulse. Accordingly, they are vital in maintaining the flow of a transmitted signal from nerve to nerve. Blocking nerve transmissions inhibits the means by which the body can initiate the movement of muscles. The result is paralysis. This paralysis produces a variety of symptoms including double or blurred vision, drooping eyelids, slurred speech, difficulties in swallowing, muscle weakness, paralysis of limbs and respiratory muscles.
The appearance of the symptoms of botulism vary depending on the route of toxin entry. For example, ingestion of toxin-contaminated food usually leads to symptoms within two to three days. However, symptoms can appear sooner or later depending on whether the quantity of toxin ingested is low or high.
The diagnosis of botulism and so the start of the appropriate therapy can be delayed, due to the relative infrequency of the malady and its similarity (in the early stages) with other maladies, such as Guillain-Barré syndrome and stroke. Diagnosis can involve the detection of toxin in the patient's serum, isolation of living bacteria from the feces, or by the ability of the patient's sample to produce botulism when introduced into test animals.
Clostridium botulinum requires an oxygen-free atmosphere to grow. Growth of the bacteria is associated with the production of gas. Thus, canned foods can display a bulging lid, due to the build-up of internal pressure. Recognition of this phenomenon and discarding of the unopened can is always a safe preventative measure.
Studies conducted by United States health authorities have shown that the different forms of the botulism toxin display some differences in their symptomatology and geographic distribution. Type A associated botulism is most prevalent in the western regions of the US, particularly in the Rocky Mountains. This toxin produces the most severe and long-lasting paralysis. Type B toxin is more common in the eastern regions of the country, especially in the Allegheny mountain range. The paralysis produced by type B toxin is less severe than with type A toxin. Type E botulism toxin is found more in the sediments of fresh water bodies, such as the Great Lakes. Finally, type F is distinctive as it is produced by Clostridium baratii.
Treatment for botulism often involves the administration of an antitoxin, which acts to block the binding of the toxin to the nerve cells. With time, paralysis fades. However, recovery can take a long time. If botulism is suspected soon after exposure to the bacteria, the stomach contents can be pumped out to remove the toxic bacteria, or the wound can be cleaned and disinfected. In cases of respiratory involvement, the patient may need mechanical assistance with breathing until lung function is restored. These measures have reduced the death rate from botulism to 8% from 50% over the past half century.
As dangerous as botulinum toxin is when ingested or when present in the bloodstream, the use of the toxin has been a boon to those seeking non-surgical removal of wrinkles. Intramuscular injection of the so-called "Botox" relaxes muscles and so relieves wrinkles. Thus far, no ill effects of the cosmetic enhancement have appeared. As well, Botox may offer relief to those suffering from the spastic muscle contractions that are a hallmark of cerebral palsy.
See also Bacteria and bacterial diseases; Bioterrorism; Food safety