What is the difference between endotoxin enterotoxin and exotoxin?
Bacteria are known to produce toxins, enzymes, and pigments in the host. The toxin can be informed of endotoxin, exotoxin, and enterotoxin.
The main difference between endotoxin, enterotoxin, and exotoxin is that endotoxin s a lipopolysaccharide found in the outer membrane of the Gram-negative bacteria, exotoxin is a protein secreted by gram-positive bacteria whereas enterotoxin is a type of exotoxin in the intestines.
Comparison Table between Endotoxin Enterotoxin and Exotoxin
| Endotoxin | Enterotoxin | Exotoxin |
| The presence inside the bacteria cell and get released when the cell disintegrates | Toxins that affect the intestine like food poisoning | Toxins released by the living bacterial cell into the surroundings |
| Lipopolysaccharide | Protein | Protein |
| 50-1000 kDa | 25-30 kDa | 10 kDa |
| O-antigen/O-polysaccharide, core oligosaccharide, and lipid A | A subunit with catalytic activity and B subunit for binding | A subunit with catalytic activity and B subunit for binding |
| The outer membrane of the Gram-negative bacteria | Gram-positive bacteria | Gram-positive bacteria |
| It is an integral part of the outer cell membrane | Type of secretory proteins | Type of secretory proteins |
| Heat stable | Heat stable | Destroyed rapidly at 60 °C |
| Weakly immunogenic | Highly antigenic | Highly antigenic |
| Pyrogenic | Cause diarrhea and food poisoning | Cause life-threatening symptoms |
| Do not have specific receptors | Have specific receptors | Have specific receptors |
| Do not produce toxoid | Produce toxoid | Produce toxoid |
| Examples are Neisseria spp. and Haemophilus spp. | Examples are Staphylococcus aureus, Bacillus cereus, and Vibrio cholera | Examples are Clostridium botulinum; Corynebacterium diphtheriae and Clostridium tetani |
| Diseases caused are septic shock and multiple sclerosis | Diseases caused are food poisoning and diarrhea | Diseases caused are tetanus, diphtheria, and botulism. |
| Do not get denatured | Get denatured by boiling | Get denatured by boiling |
| Do not prove fatal | Tend to be fatal in larger quantities | Tend to be fatal in larger amounts |
What Is Endotoxin?
Endotoxin is a lipopolysaccharide presence on the outer membrane of the gram-negative bacteria cell wall. It increases the negative charge of the cell membrane to maintain the structure.
Examples of endotoxin are Salmonella typhi (Typhoid), Vibrio cholerae (Cholera). And Streptococcus pneumoniae (sepsis)
What Is Enterotoxin?
Enterotoxin is a type or exotoxin that tend to target the intestines. It can be coded either chromosomally or in plasmids.
They are heat stable and secreted to the outside by Staphylococcus aureus, Bacillus cereus, and Vibrio cholera.
What Is Exotoxin?
Exotoxin is a type of secretory protein of Gram-positive bacteria and some Gram-negative bacteria. It can cause disruption to the host cells hence affecting metabolism.
They are highly toxic and immunogenic. Examples are botulinum toxin produced by Clostridium botulinum, diphtheria toxin produced by Corynebacterium diphtheriae toxin, and tetanospasmin produced by Clostridium tetani. And, all of the three toxins are neurotoxins.
Main Difference between Endotoxin Enterotoxin and Exotoxin
- Endotoxin is a lipopolysaccharide, enterotoxin is a type of exotoxin while exotoxin is a protein
- Both enterotoxin and exotoxin comprise of two parts while endotoxin comprise of three parts
- Both enterotoxin and exotoxin are produced by gram-positive bacteria while endotoxin is produced by the outer membrane of gram-negative bacteria
- Endotoxin is an integral part of the outer membrane while both enterotoxin and exotoxin are secretory protein
- Endotoxin and enterotoxin are heat resistant while exotoxin get denature at 60 degrees
- Both enterotoxin and exotoxin are highly immunogenic whereas endotoxin is weakly immunogenic
Similarities between Endotoxin Enterotoxin and Exotoxin
- Both are types of toxins produced by pathogens
- Both are virulence factors
- Both cause diseases
Frequently Asked Questions (Endotoxin vs Enterotoxin vs Exotoxin)
Is Staphylococcus Aureus Endotoxin Or Exotoxin?
Exotoxin. They are specific to particular bacterial strains. It has a high immunogenic and tends to be fatal in large quantities.
Does Staphylococcus Aureus Produce Endotoxin?
Yes. They produce a wide variety of exoproteins that contribute to its ability to colonize and cause disease in mammalian hosts.
How Do Exotoxins and Endotoxins Cause Infections?
The endotoxins release the toxins only when the bacteria are killed, whereas, the exotoxins release toxins immediately into the environment.
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Comparison Video
Summary
The core difference between endotoxin enterotoxin and exotoxin is that endotoxin is an integral part of the outer membrane of the bacterial cell and release upon the disintegration of the cell, enterotoxin is a type of exotoxin while exotoxin is secreted as part of metabolism.
More Sources and References
- Gram-Positive and Gram-Negative Bacterial Toxins. NCBI
- Mechanism of Pathogenicity. Slide Share