What do exotoxins do?

Exotoxins are a group of soluble proteins that are secreted by the bacterium, enter host cells, and catalyze the covalent modification of a host cell component(s) to alter the host cell physiology. Both Gram-negative and Gram-positive bacteria produce exotoxins.

What is endotoxin vs exotoxin and their mechanism of action?

Classically, bacterial toxins are divided into exotoxins and endotoxins. While endotoxins are membrane compounds of Gram-negative bacteria which elicit an inflammatory response in host, exotoxins are secreted proteins which act locally and at distance of the bacterial colonization site.

How do exotoxins benefit bacteria?

Exotoxins can be single polypeptides or heteromeric protein complexes that act on different parts of the cells. At the cell surface, they may insert into the membrane to cause damage, bind to receptors to initiate their uptake, or facilitate interactions with other cell types.

Where do exotoxins act?

Exotoxins are usually proteins, minimally polypeptides, that act enzymatically or through direct action with host cells and stimulate a variety of host responses. Most exotoxins act at tissue sites remote from the original point of bacterial invasion or growth.

Do exotoxins have specific methods of action?

According to their mechanisms of action, exotoxins can be divided into three groups: (1) acting at the surface of target cells, (2) forming pores into cell membranes, and (3) injecting inside the cell a subdomain that targets a specific cytosolic protein or organelle.

What is an endotoxin response?

Endotoxins are lipopolysaccharides found in the cell wall of Gram-negative bacteria, which can induce inflammation and fever as an immune response in higher organisms. Reaction to endotoxins can lead to anaphylactic shock and death of patients.

Why do bacteria release toxins?

Thus, toxins and other virulence determinants are simply mechanisms for gaining access to environments in our bodies and to the nutrients sequestered within them, for releasing these nutrients in usable form, and then for moving to new hosts when they are expended.