Toxin from bacteria that destroys or disrupts cells
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This figure shows that exotoxins are secreted by bacterial cells, Clostridium botulinum for example, and are toxic to somatic cells. Somatic cells have antibodies on the cell wall to target exotoxins and bind to them, preventing the invasion of somatic cells. The binding of the exotoxin and antibody forms an antigen-antibody interaction and the exotoxins are targeted for destruction by the immune system. If this interaction does not happen, the exotoxins bind to the exotoxin receptors that are on the cell surface and causes death of the host cell by inhibiting protein synthesis. This figure also shows that the application of heat or chemicals to exotoxins can result in the deactivation of exotoxins. The deactivated exotoxins are called toxoids and they are not harmful to somatic cells.
An exotoxin is a toxin secreted by bacteria.[1] An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host. Exotoxins may be secreted, or, similar to endotoxins, may be released during lysis of the cell. Gram negative pathogens may secrete outer membrane vesicles containing lipopolysaccharide endotoxin and some virulence proteins in the bounding membrane along with some other toxins as intra-vesicular contents, thus adding a previously unforeseen dimension to the well-known eukaryote process of membrane vesicle trafficking, which is quite active at the host–pathogen interface.
They may exert their effect locally or produce systemic effects. Well-known exotoxins include: botulinum toxin produced by Clostridium botulinum; Corynebacterium diphtheriae toxin, produced during life-threatening symptoms of diphtheria; tetanospasmin produced by Clostridium tetani. The toxic properties of most exotoxins can be inactivated by heat or chemical treatment to produce a toxoid. These retain their antigenic specificity and can be used to produce antitoxins and, in the case of diphtheria and tetanus toxoids, are used as vaccines.
Exotoxins are susceptible to antibodies produced by the immune system, but some exotoxins are so toxic that they may be fatal to the host before the immune system has a chance to mount defenses against them. In such cases, antitoxin, anti-serum containing antibodies, can sometimes be injected to provide passive immunity.
^Ryan, Kenneth J.; Ray, C. George, eds. (2010). Sherris medical microbiology (5th ed.). New York: McGraw Hill Medical. ISBN 978-0-07-160402-4.
An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They...
The Pseudomonas exotoxin (or exotoxin A) is an exotoxin produced by Pseudomonas aeruginosa. Vibrio cholerae produces a similar protein called the Cholix...
Streptococcal pyrogenic exotoxins also known as erythrogenic toxins, are exotoxins secreted by strains of the bacterial species Streptococcus pyogenes...
the cause of scarlet fever, which results from exposure to the species' exotoxin. Unlike most bacterial pathogens, S. pyogenes only infects humans. Thus...
be red and bumpy. The rash occurs as a result of capillary damage by exotoxins produced by S.pyogenes. On darker-pigmented skin the rash may be hard...
sudotox is a form of recombinant CD4 derived from Pneumonas aeruginosa exotoxin A, or 'PE40, which has a size of 59,187 daltons and is an anti-viral agent...
from mobile genetic elements like plasmids and bacteriophages (e.g. some exotoxins). Virulence factors encoded on mobile genetic elements spread through...
differently from humans and other animals. C. tetani also produces the exotoxin tetanolysin, a hemolysin, that causes destruction of tissues. Tetanus toxin...
Diphtheria toxin is an exotoxin secreted mainly by Corynebacterium diphtheriae but also by Corynebacterium ulcerans and Corynebacterium pseudotuberculosis...
soil-borne anaerobic bacteria. Bacteria cause myonecrosis by specific exotoxins. These microorganisms are opportunistic and, in general, enter the body...
kidney failure.[citation needed] The syndrome is induced by epidermolytic exotoxins (exfoliatin) A and B, which are released by S. aureus and cause detachment...
A toxoid is an inactivated toxin (usually an exotoxin) whose toxicity has been suppressed either by chemical (formalin) or heat treatment, while other...
An enterotoxin is a protein exotoxin released by a microorganism that targets the intestines. They can be chromosomally or plasmid encoded. They are heat...
be treated as a medical emergency. Gas gangrene is caused by bacterial exotoxin-producing clostridial species, which are mostly found in soil, and other...
lethality, as the lethality and symptoms themselves are caused by the exotoxin produced by the bacteria. Diagnosis can often be made based on the appearance...
Each is a thermolabile protein of ~80kDa. PA forms the "B" part of the exotoxin and allows passage of the "A" moiety (consisting of EF or LF) into target...
endotoxin by Richard Friedrich Johannes Pfeiffer. He distinguished between exotoxins, toxins that are released by bacteria into the surrounding environment...
Pertussis toxin (PT) is a protein-based AB5-type exotoxin produced by the bacterium Bordetella pertussis, which causes whooping cough. PT is involved in...
serine protease HtrA (high temperature requirement A), and the major exotoxins CagA and VacA. The presence of VacA and CagA are associated with more...
primarily affecting the respiratory tract and the subsequent release of an exotoxin. The toxin has a localized effect on skin lesions, as well as a metastatic...
nervous system On a broader scale, toxins may be classified as either exotoxins, excreted by an organism, or endotoxins, which are released mainly when...
numbers of C. perfringens grow in the intestines, and secrete exotoxin. This exotoxin causes necrosis of the intestines, varying levels of hemorrhaging...
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