Bug | Mode of Action |
Clostridium tetani | blocks the release of the inhibitory NTs glycine & GABA in interneurons of the spinal cord; causes 'lockjaw', risus sardonicus, opisthotonos & tetanic paralysis of respiratory muscles |
Clostridium botulinum | blocks the release of ACh at NMJs; causes antiCh sxs, CNS paralysis (flaccid muscles), constipation; spores found in canned food, honey causes floppy baby, most potent exotoxin |
Corynebacterium diphtheria | inactivates EF-2 by ADP ribosylation which - protein synthesis; causes pharyngitis & 'pseudomembrane' in throat, then binds to heart & neural tissue, myocarditis w/ arrhythmias or circulatory collapse, paralysis of pharyngeal muscles & peripheral neuritis |
Staphylococcus aureus' alpha toxin | creates holes in cell membrane, allowing easy transit of substances into and out of the cell to yield eventual cell death, causes marked necrosis of skin and hemolysis |
Clostridium perfringens | alpha toxin is a lecithinase; causes gas gangrene; get double zone of hemolysis on bld agar |
Staphylococcus aureus (Toxic Shock Syndrome Toxin) | superantigen that binds to MHC-2 protein (antigen-presenting cells) & T-cell receptor, inducing IL-1 & IL-2 synthesis in TSS; also causes food poisoning, induces cytokines like IL-1, causes fever, rash, desquamation, diarrhea, hypoTN then shock |
Vibrio cholerae | binds gangliosides (glycolipids line outer layer of plasma membranes) in intestinal cell; + Gs protein -> + adenylate cyclase -> overprod of cAMP -> secretion of Cl ions & H2O -> massive watery diarrhea w/o WBCs, voluminous rice-water stool |
Bordetella pertussis | + adenylate cyclase by ADP ribosylation; causes whooping cough; - chemokine receptor, causing lymphocytosis, also - ciliary movement by binding onto respiratory tract epithelial cells and lymphocytes = copious mucus |