, especially a protein or conjugated protein produced by certain animals, higher plants, and pathogenic bacteria. Bacterial toxins characteristically do not cause symptoms until after a period of incubation while the microbes multiply, or (as happens with botulism) the preformed toxin reaches and affects the tissue. Usually only a few toxin-producing agents are introduced into the body, and it is not until there are enough of them to overwhelm the leukocytes and other types of antibodies that symptoms occur. In some cases of food poisoning, symptoms are almost immediate because the toxin is taken directly with the food. Toxins can cause antitoxins to form in the body, thus providing a means for establishing immunity
to certain diseases.
) (botulinus toxin
) one of seven type-specific, immunologically differentiable exotoxins
(types A to G) produced by Clostridium botulinum,neurotoxins
usually found in imperfectly canned or preserved foods. They cause botulism
by preventing release of acetylcholine
by the cholinergic fibers. Type A is one of the most powerful poisons known; it is also used therapeutically by injection to inhibit muscular spasm in the treatment of dystonic disorders such as blepharospasm
, to treat wrinkles of the upper face, and to reduce anal sphincter pressure to promote healing of chronic anal fissure
. Type B is injected in treatment of cervical dystonia. Called also botulin
produced by Vibrio cholerae;
a protein enterotoxin
that binds to the membrane of enteric cells and stimulates the adenylate cyclase
system, causing the hypersecretion of chloride and bicarbonate ions, resulting in increased fluid secretion and the severe diarrhea characteristic of cholera
a protein exotoxin
produced by Corynebacterium diphtheriae
that is primarily responsible for the pathogenesis of diphtheria
and related infections; it is an enzyme that activates transferase II of the mammalian protein synthesizing system.
diphtheria toxin for Schick test
a sterile solution of the diluted, standardized toxic products of Corynebacterium diphtheriae;
used as a dermal reactivity indicator in the schick test
of immunity to diphtheria
any of various exotoxins
produced by species of Shigella;
the one formed by S. dysenteriae
serotype 1 is a potent neurotoxin
with hemorrhagic and paralytic properties.
a bacterial toxin from certain strains of Streptococcus pyogenes
that produces an erythematous reaction when injected intradermally and is responsible for the rash in scarlet fever
gas gangrene toxin
that causes gas gangrene
; there are at least 10 types produced by Clostridium perfringens
and others produced by C. noriyi
and C. septicum.
the potent exotoxin produced by Clostridium tetani,
consisting of two components, one a neurotoxin (tetanospasmin)
and the other a hemolysin (tetanolysin)
toxin /tox·in/ (tok´sin) a poison, especially a protein or conjugated protein produced by some higher plants, certain animals, and pathogenic bacteria, that is highly poisonous for other living organisms.
bacterial toxins toxins produced by bacteria, including exotoxins, endotoxins, and toxic enzymes.
, botulinum toxin
, botulinus toxin
an exotoxin produced by Clostridium botulinum
that produces paralysis by blocking the release of acetylcholine in the central nervous system; there are seven immunologically distinct types (A–G). Type A is used therapeutically to inhibit muscular spasm in the treatment of dystonic disorders such as blepharospasm and strabismus, as well as to treat wrinkles of the upper face; type B is used to treat cervical dystonia.
one produced by species of Clostridium,
including those causing botulinus, gas gangrene, and tetanus.
a protein exotoxin produced by Corynebacterium diphtheriae
that is primarily responsible for the pathogenesis of diphtheritic infection; it is an enzyme that inhibits protein synthesis.
gas gangrene toxin
an exotoxin produced by Clostridium perfringens
that causes gas gangrene; at least 10 types have been identified.
a poison, especially a protein or conjugated protein produced by certain animals, some higher plants, and pathogenic bacteria. Antigenic toxins
, produced by bacteria or helminths, stimulate production of antitoxins. Exotoxins are produced by bacteria and diffuse into surroundings, e.g. tetanus toxin, or can be ingested preformed, e.g. botulinum toxin. Endotoxins are released into the surrounding tissue only when the bacteria break down. They are lipopolysaccharides and form part of the cell wall, e.g. coliform endotoxins. Metabolic toxins
, e.g. toxic amines absorbed from damaged intestine, ketones, lactic acid from carbohydrate engorgement, ammonia in liver damage, creatinine in renal dysfunction. See also metabolic
an exotoxin produced by certain bacteria that causes extensive local necrosis on intradermal inoculation.
the potent neurotoxic exotoxin produced by Clostridium tetani. Called also tetanospasmin.