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 ?
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.
Three exotoxins are also produced, which mediate shock and multiple system organ failure.
Penicillin and clindamycin differentially inhibit the production of pyrogenic exotoxins A and B by group A streptococci.
Neurotoxins are either endotoxins or exotoxins attracted to the host nervous system.
Streptococcal pyrogenic exotoxins also play a major role in the pathogenesis of GAS infections by acting as superantigens.
These may affect cellular function in the host in specific ways: the exotoxins produced by Bordetella pertussis inhibit mucociliary clearance from the respiratory tract and trigger inflammation and necrosis of the epithelial lining of the tract.
Such strains which have ability to produce specific exotoxins, in the absence of type specific immunity in a population, may lead to a community outbreak of streptococcal infections.
Rickettsiae do not produce exotoxins, and an important virulence mechanism is inducing oxidative stress on host cells.
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.
CRS may be the result of allergic inflammation, bacterial and/ or fungal infection, or superantigen exotoxins released by bacteria, according to the report.