What are exotoxins and endotoxins?
What are exotoxins and endotoxins?
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.
WHAT IS A exotoxin definition?
Defining Statement 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 an example of an exotoxin?
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.
What are characteristics of exotoxins?
Some of the differences between Exotoxins and Endotoxins are as follows:
| S.N. | Exotoxins | Endotoxins |
|---|---|---|
| 3 | It is polypeptide | It is lipopolysaccharide complex. |
| 4 | Relatively unstable, heat labile (60°C) | Relatively stable, heat tolerant |
| 5 | Highly antigenic | Weakly immunogenic |
| 6 | Toxoids can be madeby treating with formalin | Toxoids cannot be made |
What is an example of endotoxin?
Endotoxin: Examples In bacteriology, this complex compound is also known as lipopolysaccharide and can be found on the outer membranes of bacteria like Escherichia coli, Salmonella shigella, Vibrio cholerae, and Haemophilus influenzae.
What do endotoxins do?
Endotoxin is a lipopolysaccharide contained within the cell wall of Gram-negative bacteria. This molecule initiates a host inflammatory response to Gram-negative bacterial infection. An adequate inflammatory response likely enhances host survival by mediating clearance of infection and bacterial toxins.
What is an example of an endotoxin?
Where are exotoxins found?
Genes – For the most part, genes involved in the production of exotoxins can be found in plasmid or bacteriophage (extrachromosomal DNA). Those involved in the production of endotoxins are typically found in the bacterial chromosome.
What disease is caused by endotoxin?
Peripheral diseases that elevate blood endotoxin, such as sepsis, AIDS and liver failure, also result in neurodegeneration. Endotoxin directly and indirectly activates microglia that damage neurons via nitric oxide, oxidants and cytokines, and by phagocytosis of synapses and neurons.
How do endotoxins harm humans?
While it is not an infectious particle, endotoxin is biologically active material derived from bacteria that can affect many human organ systems and disrupt humoral and cellular host mediation systems. Symptoms of exposure to airborne exposure include chest tightness, cough, shortness of breath, fever, and wheezing.