Shiga toxin

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Shiga toxin

the endotoxin formed by Shigella dysenteriae type 1.

Shi·ga tox·in

(shē'gah tok'sin)
The endotoxin formed by Shigella dysenteriae type 1.

Shiga toxin

An extremely poisonous compound secreted by enteric bacteria that causes hemorrhagic and necrotic colitis. The toxin was formerly called verotoxin because of its effect on Vero cells.

Etiology

The toxin acts on the endothelial cells lining the blood vessels. The B subunits of the toxin bind to a component of the cell membrane known as Gb3 and enter the cell. When the protein is inside the cell, the A subunit interacts with the ribosomes to stop protein synthesis. Like the ricin toxin, the A subunit of Shiga toxin is an N-glycosidase that modifies the RNA component of the ribosome to stop protein synthesis, leading to the death of the cell. The breakdown of the endothelial cell lining leads to hemorrhage.

Symptoms

The first sign of shiga toxin activity is usually bloody diarrhea. This is because Shiga toxin is usually taken in with contaminated food or water.

See also: Shiga, Kiyoshi
References in periodicals archive ?
Multicenter evaluation of a sequence-based protocol for subtyping Shiga toxins and standardizing Stx nomenclature.
Antibodies used in current tests only recognize a subset of Shiga toxins, but not all Shiga toxins.
The new antibody-based assay identifies all known subtypes of Shiga toxins produced by STEC and has been tested in various studies by He, research leader Luisa Cheng, biologist Larry Stanker, and former ARS postdoctoral research associate Craig Skinner.
Shiga toxins belong to a large family of bacterial toxins with two major groups, stx1 and stx2.
Kasetkowy second immunochromatographic rapid test for the detection of Shiga toxins 1 and 2 (Verotoksyn) produced by E.
For Embase/Medline and Scopus, we used a combined search of the following concepts and their Emtree synonyms: Shiga Toxins, Shigella, and Hemolytic Uremic Syndrome.
Shiga toxins represent a group of bacterial toxins that are involved in the most serious forms of food poisoning.
When found to have shiga toxins, the specimens would be sent to a reference laboratory abroad through the World Health Organisation (WHO).
This family of toxins was subsequently also called Shiga-like toxins (SLT), and more recently Shiga toxins (Stx), because of the close relation to the Stx of Shigella dysenteriae type 1.
Two types of Shiga toxins, Stx1 and Stx 2, are known and constitute the main virulence factors in STEC strains (PATON & PATON, 1998).
Shigella dysenteriae, just like many other bacteria, excrete toxins such as Shiga toxins (Stx's), which cause serious complications during infection (Paton & Paton, 1998).
The best way to identify all STEC infections is to screen all stool samples submitted for routine enteric bacterial testing for Shiga toxins (Stxs) using enzyme immunoassay (EIA) or polymerase chain reaction.