Extoxins Versus Endotoxins

Bacteria produce 2 types of toxins: exotoxins & endotoxins

EXOTOXINS ENDOTOXINS
Proteins Lipopolysaccharides (LPS)
Heat labile Heat stable
Secreted by cells Part of cell wall
Generally produced by Gram positive bacteria.
Exception - Can be from following Gram negative bacteria: Shigella, E.coli & Vibrio Cholerae From Gram negative bacteria
Diffuse into surrounding medium Do not diffuse into surrounding medium
Readily separable from cultures by physical means such as filtration Obtained only by cell lysis
Action often enzymatic No enzymatic action
Specific pharmacological effect for each Nonspecific action (action common to all)
Specific tissue affinities No specific tissue affinity
Active in very minute doses Active only in very large doses
Highly antigenic Weakly antigenic
Action specifically neutralized by antibody Neutralization by antibody ineffective