AAT Bioquest

What toxins are produced by gram negative bacteria?

Posted March 2, 2023


Gram negative bacteria produce different types of toxins including: 

Type II Toxins 

Type II toxins include exotoxins that damage the cell membrane. Leukotoxins, Pseudomonas aeruginosa toxins, and Clostridium perfringens exotoxins are examples of Type II toxins.  

Type III Toxins

Type III toxins are A/B toxins. They are also known as intracellular effector toxins and are characterized by the "A" and "B" regions. Examples of type III exotoxins include botulism exotoxin, cholera exotoxin, anthrax toxins, and shiga toxin. 

 Type I Toxins

Membrane-acting toxins are classified as Type I toxins or superantigens. These toxins stimulate transmembrane signals by binding to surface receptors of host cells. Streptococcal superantigen, Streptococcal mitogenic exotoxin, Streptococcal pyrogenic exotoxins, and Enterotoxogenic E. coli enterotoxin are examples of Type 1 toxins.

Additional resources

Virulence factors of gram-negative bacteria in sepsis with a focus on Neisseria meningitidis

Gram Staining

MycoLight™ Rapid Fluorescence Gram-Positive Bacteria Staining Kit