exotoxin

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Related to Exotoxins: Endotoxins

exotoxin

 [ek´so-tok″sin]
a potent toxin formed and excreted by the bacterial cell and found free in the surrounding medium; exotoxins are the most poisonous substances known. They are protein in nature and heat labile, and are detoxified with retention of antigenicity by treatment with formaldehyde. Bacteria of the genus Clostridium are the most frequent producers of exotoxins; diphtheria, botulism, and tetanus are all caused by such toxins. adj., adj ex´otoxic.

ex·o·tox·in

(ek'sō-tok'sin),
A specific, soluble, antigenic, usually heat labile, injurious substance elaborated by certain gram-positive or gram-negative bacteria; it is formed within the cell, but is released into the environment where it is rapidly active in extremely small amounts; most exotoxins are proteinaceous (MW 70,000-900,000) and can have the toxic portion of the molecule destroyed by heat, prolonged storage, or chemicals; the nontoxic but antigenic form is a toxoid.

exotoxin

/exo·tox·in/ (ek´so-tok″sin) a potent toxin formed and excreted by the bacterial cell, and free in the surrounding medium.ex´otoxic
streptococcal pyrogenic exotoxin  one produced by Streptococcus pyogenes, existing in several antigenic types and causing fever, the rash of scarlet fever, organ damage, increased blood-brain barrier permeability, and alterations in immune response.

exotoxin

(ĕk′sō-tŏk′sĭn)
n.
A poisonous substance secreted by a microorganism and released into the medium in which it grows.

exotoxin

[ek′sətok′sin]
Etymology: Gk, exo + toxikon, poison
a toxin that is secreted or excreted by a living microorganism. Compare endotoxin.

ex·o·tox·in

(eks'ō-tok'sin)
A specific, soluble, antigenic, usually heat labile, injurious substance elaborated by some bacterial species; it is formed within the cell but is released into the environment where it is rapidly active in extremely small amounts; most exotoxins are proteinaceous in nature.
Synonym(s): extracellular toxin.

exotoxin

A powerful protein poison, formed by some bacteria, which is released and which may cause severe damage either locally or, if carried away by the blood, at a remote distance. Diphtheria exotoxin destroys throat lining tissue, where the organism settles, but can also travel to damage the heart and the kidneys.

exotoxin

a poison produced by a living CELL and released into the environment. It can affect various ORGANS and systems of the body.

Exotoxin

A poisonous secretion produced by bacilli which is carried in the bloodstream to other parts of the body.
Mentioned in: Diphtheria

exotoxin

antigenic and harmful chemical released from some Gram-positive bacteria

ex·o·tox·in

(eks'ō-tok'sin)
A specific, soluble, antigenic, usually heat labile, injurious substance elaborated by certain gram-positive or gram-negative bacteria.

exotoxin (ek´sōtoksin),

n the toxic material formed by microorganisms and subsequently released into their surrounding environments.

exotoxin

a potent toxin formed and secreted by the bacterial cell, and found free in the surrounding medium.
Exotoxins are generally heat labile, and are protein in nature. Many can be detoxified with retention of antigenicity by treatment with formaldehyde (toxoid). Many are important virulence factors in pathogenic bacteria.
References in periodicals archive ?
Scarlet fever is caused by a limited number of Streptococcus pyogenes lineages and is associated with the exotoxin genes ssa, speA and speC.
GAS secretes several pyrogenic exotoxins including SpeA, SpeB, SpeC, and SpeD.
Protection against Exotoxin A (ETA) and Pseudomonas aeruginosa Infection in Mice with ETA-Specific Antipeptide Antibodies.
perfringens type D isolates were proved to contain alpha and epsilon exotoxins which gave characteristic bands at 1167 and 960 bp respectively.
The gene for type A streptococcal exotoxin (erythrogenic toxin) is located in bacteriophage T12.
These exotoxins may be extremely potent and cause forms of toxic shock syndrome that may be fatal.
Studies have shown, beside the possible mechanisms listed above, that glycerol monolaurate (Lauricidin [R]), also inhibits the production of a variety of exotoxins.
Bacteria often occur in large numbers, forming bacterial nets that attach to necrotized surfaces, suggesting that powerful exotoxins are produced to attenuate host defense responses (Baxa et al.
Examples of such toxins include endotoxins and exotoxins from bacteria, toxic amines, toxic derivatives from bile and many carcinogens.
Other possible causes of the inflammatory response can be the metabolic alteration associated with bowel obstruction, or the breaching of the anatomic mucosal or epithelial barriers to exotoxins produced by altered flora.
Clostridium difficile is a spore-forming, gram-positive bacillus that produces exotoxins that are pathogenic to humans.
Naomi Balaban at the University of California, Davis has done considerable work on the use of RNAIII inhibiting protein (RIP) (2,3), both alone and in combination with antibiotics and with the antimicrobial peptide dermaseptin b to inhibit production of biofilms and exotoxins by S.