CHOLERA EXOTOXIN Meaning and
Definition
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Cholera exotoxin refers to a toxic substance produced by the bacterium Vibrio cholerae, specifically the serogroups O1 and O139, which are responsible for causing cholera in humans. This highly potent exotoxin is a key virulence factor for the bacterium, playing a crucial role in the development of the characteristic symptoms and severe clinical manifestations associated with the disease.
The exotoxin is composed of two subunits, designated as A and B. The A subunit possesses enzymatic activity, acting as an ADP-ribosyltransferase. It targets and modifies a host cell protein known as regulatory Gsα protein, which regulates the activity of adenylate cyclase. By modifying Gsα, the toxin disrupts the control mechanism of adenylate cyclase, leading to excessive production of cyclic adenosine monophosphate (cAMP) within the host cell.
This excessive increase in cAMP levels triggers a cascade of intracellular events, leading to hypersecretion of chloride ions and water into the intestinal lumen. This, in turn, results in profuse watery diarrhea, one of the hallmark symptoms of cholera.
Cholera exotoxin is heat-labile and can be inactivated at temperatures above 60 degrees Celsius. However, it is rapidly absorbed from the gastrointestinal tract before reaching the large intestine, where its effects are primarily exerted. The toxin's action leads to the characteristic rapidly dehydrating diarrhea observed in cholera patients, potentially leading to severe dehydration, electrolyte imbalances, and, if left untreated, may even result in death.
Common Misspellings for CHOLERA EXOTOXIN
- xholera exotoxin
- vholera exotoxin
- fholera exotoxin
- dholera exotoxin
- cgolera exotoxin
- cbolera exotoxin
- cnolera exotoxin
- cjolera exotoxin
- cuolera exotoxin
- cyolera exotoxin
- chilera exotoxin
- chklera exotoxin
- chllera exotoxin
- chplera exotoxin
- ch0lera exotoxin
- ch9lera exotoxin
- chokera exotoxin
- chopera exotoxin
- chooera exotoxin
- cholwra exotoxin
Etymology of CHOLERA EXOTOXIN
The word "cholera" originates from the ancient Greek word "kholera" (χολέρα), which means "bile" or "yellow bile". This term was used because people believed that the disease caused an excessive production of bile, leading to its characteristic symptoms.
The term "exotoxin" is composed of two parts: "exo-" and "-toxin". "Exo-" is derived from the Greek word "exo" (ἔξω), which means "outside" or "outer". "-Toxin" is derived from the Latin word "toxicum", meaning "poison". Therefore, "exotoxin" refers to a toxin produced by certain bacteria or other microorganisms that is released outside the cell and can cause harm to the host organism.
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