What are Cholera Toxins?

Cholera toxins are a group of proteins responsible for the extreme diarrhea associated with cholera. Once vibrio cholerae, the bacteria responsible for cholera, has infected an individual, it produces cholera toxins. These toxins then latch onto cells in the small intestine called enterocytes. Once inside the cells of the small intestine, the toxin causes secretion of water, sodium and other substances. This liquid then fills the small intestine and results in severe diarrhea. The term cholera toxins are sometimes shortened as CTX, CT, or Ctx.

All bacteria create toxins that serve the bacteria as a form of protection. They kill cells so that the bacteria can continue to reproduce and thrive. Cholera toxins are a form of protection for vibrio cholerae.

Cholera toxins are composed of six protein subunits. These six subunits come from two different protein units, A and B. A replica of A is one subunit, while five replicas of B compose the second subunit. The A subunit is enzymatic, which means that it helps to start the chemical reaction in the cells that create the diarrhea. The B subunits are receptor binding, meaning that they help the toxin attach itself to the cells.

Cholera and cholera toxins have both been studied extensively. Learning about how the bacteria thrives in the body, in the acidic stomach environment, and continues to evolve has other implications. Through learning about cholera, scientist better understand how bacteria changes over time to resist developed treatments. In turn, this can lead to more effective treatments over time.

Researching cholera toxins also has important implications in the treatment of cholera specifically. This toxin is responsible for diarrhea, which is the most devastating aspect of the bacteria. Treatments that could interfere with the development or process of the toxins could have a huge impact in helping to decrease the suffering associated with cholera.

Through research and testing on the B subunit of the cholera toxin, it was found that the B proteins are not toxic. This was a valuable discovery in molecular biology. Now the B subunit of cholera toxins is used to find and track cells during experiments.

Despite the life threatening diarrhea that is caused by cholera toxins, if the disease is treated it is rarely fatal. Individuals suffering from cholera are treated by rehydrating the body and also by replacing the important electrolytes lost from diarrhea and vomiting. Antibiotics are sometimes used as well, but are not always necessary if patients are continuously hydrated.