Bacterial Toxins:
Endotoxins-
- Heat-stable toxins
- Intracellular toxin (inside)
- Associated within the outer membranes of certain Gram-negative bacteria, such as Brucella, Neisseria meningitidis, Vibrio cholerae, Bordetella pertussis
- They are not secreted, rather they are released only when the cells are disrupted or lysed
- They are less potent and less specific than exotoxins
- Do not form toxoids
- If released in large quantities, they produce hemorrhagic shock and severe diarrhea, chills, weakness, lightheadedness
- Smaller amounts are responsible for fever, altered resistance to bacterial infection, leukopenia followed by leukocytosis, other symptoms
- Interleukin 1 and 2
- Histamine
- Tumor necrosis factor
- Activation of coagulation cascade
- Prostaglandin (pain)
- Thromboxane
- Leukotriene
- Prostacyclin
- Beta-endorphins
- Bradykinin
- Oxygen-derived free radicals (cell damage)
- Platelet activating factor
- Anaphylatoxins C5a and C3a
- Myocardial depressant factor
- Affect cells of the intestinal mucosa
- Entero-in between (endothelium affected and penetrated by these toxins)
- Cause vomiting and diarrhea
- A cytotoxin
- Heat-stable
- Food poisoning
- Causes a net fluid secretion (secretory)
- Example: cholera (V. cholerae)
- Bacillus cereus food poisoning, Clostridium difficile, E. coli (enterohemorrhagic, enteroaggregative, enterotoxogenic), Staphylococcus aureus food poisoning, Vibrio vulnificus and parahemolyticus)
- Potent toxins formed and EXCRETED by the bacterial cell to the exterior/outside
- Exits the cell and gets into the bloodstream
- Found FREE in the surrounding medium (formed first within the cell, but then is excreted via vesicles or exocytosis released into the environment where it is rapidly activated in extremely minute amounts)
- The most poisonous substances known to man
- Heat-labile proteins
- Toxoid
- Clostridium spp are the most frequent producers of these
- C. diphtheriae, C. botulinum, C. tetani produce such toxins
- S. pyogenes: fever, rash, scarlet fever