C8.3 - Endotoxins and Exotoxins Table Flashcards
Botulism - Bacterium and Type of Exotoxin
Clostridium botulinum / A-B
Tetanus - Bacterium and Type of Exotoxin
Clostridium tetani / A-B
Diphtheria - Bacterium and Type of Exotoxin
Corynebacterium diphtheriae / A-B
Scalded skin syndrome - Bacterium and Type of Exotoxin
Staphylococcus aureus / A-B
Cholera - Bacterium and Type of Exotoxin
Vibrio cholerae / A-B
Traveler’s diarrhea - Bacterium and Type of Exotoxin
Enterotoxigenic E. coli (ETEC) and Shigella spp. / A-B
Anthrax - Bacterium and Type of Exotoxin
Bacillus anthracis / A-B
Botulism - Mechanism
Neurotoxin prevents the transmission of nerve impulses → flaccid paralysis
Tetanus - Mechanism
Neurotoxin blocks nerve impulses to muscle relaxation pathway → spastic paralysis
Diphtheria - Mechanism
Cytotoxin inhibits protein synthesis (esp. in nerve, heart, and kidney cells)
Scalded skin syndrome - Mechanism
Causes skin layers to separate and slough off (scalded skin)
Cholera - Mechanism
Enterotoxin causes secretion of large amounts of fluids and electrolytes that result in diarrhea
Anthrax - Mechanism
Two A components enter the cell via the same B. The A protein causes shock and reduce the immune response.
Traveler’s diarrhea - Mechanism
Enterotoxin causes secretion of large amounts of fluids and electrolytes that result in diarrhea
Gas gangrene and food poisoning - Mechanism
One exotoxin (cytotoxin) causes massive RBC destruction (hemolysis); another exotoxin
(enterotoxin) is related to food poisoning and causes diarrhea
Antibiotic-associated diarrhea - Mechanism
Enterotoxin causes secretion of fluids and
electrolytes that results in diarrhea; cytotoxin disrupts host cytoskeleton
Food poisoning - Mechanism
Enterotoxin causes secretion of fluids and
electrolytes that results in diarrhea
Toxic shock syndrome (TSS) - Mechanism
Toxin causes secretion of fluids and electrolytes from capillaries that decreases
blood volume and lowers blood pressure
Gas gangrene and food poisoning - Bacterium and Type of Exotoxin
Clostridium perfringens and other species of Clostridium / Membrane-disrupting
Antibiotic-associated diarrhea - Bacterium and Type of Exotoxin
Clostridium difficile / Membrane-disrupting
Food poisoning - Bacterium and Type of Exotoxin
Staphylococcus aureus / Superantigen
Toxic shock syndrome - Bacterium and Type of Exotoxin
Staphylococcus aureus / Superantigen
Exotoxin - Organism Type
Gram-positive and gram-negative
Endotoxin - Organism Type
Gram-negative
Exotoxin - Chemical Nature
Protein
Endotoxin - Chemical Nature
Lipopolysaccharide
Exotoxin - Location
Outside the living cell; produced extracellularly even though the cells are intact and viable
Endotoxin - Location
Part of the outer membrane; produced only when the cell are lysed
Heat Stability - Exotoxin
Heat-labile(inactivated at 60°C)
Heat Stability - Endotoxin
Heat-stable (121°C)
Immunogenicity - Exotoxin
Highly potent and antigenic
Immunogenicity - Endotoxin
Less potent and antigenic
Toxoid Conversion - Exotoxin
Converted to toxoid
Toxoid Conversion - Endotoxin
Cannot be converted to toxoid
Detoxification by Formaldehyde - Exotoxin
Detoxified
Detoxification by Formaldehyde - Endotoxin
Not Detoxified
Neutralization by homologous antibody - Exotoxin
Complete
Neutralization by homologous antibody - Endotoxin
Partial
Toxicity - Exotoxin
High
Toxicity - Endotoxin
Low
Genetics - Exotoxin
Frequently controlled by extrachromosomal genes (eg, plasmids)
Genetics - Endotoxin
Synthesis directed by chromosomal genes
Receptor - Exotoxin
Usually bind to specific receptor on cells
Receptor - Endotoxin
Specific receptor not found on cell
Pharmacologic - Exotoxin
SPECIFIC:
* Cytotoxin
* Enterotoxin
* Neurotoxin
* Cardiotoxin
* Hepatotoxin
* Leukotoxin
Pharmacologic - Endotoxin
NONSPECIFIC: chills, fever, weakness, generalized aches, hypotension (leading to shock/septic shock), DIC (Disseminated Intravascular Coagulation)
MOA: induces production of IL-1 and IFN-α; in cases of shock, TNF/cachectin is also produced
Effects on Host - Exotoxin
Destroys a particular part of the host’s cell
Effects on Host - Endotoxin
Disruption of clotting (DIC), fever, hypotension, shock and death
Example of Exotoxin
Diphtheria toxin
Tetanus toxin
Botulinum toxin
Vibrio enterotoxin
Erythrogenic toxin
Heat labile enterotoxin
Staphylococcal enterotoxin
Example of Endotoxin
Typhoid fever - Salmonella tyhpi
UTI – Proteus spp.
Meningococcal meningitis – N. meningitidis