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18 Cards in this Set
- Front
- Back
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Corynebacterium diptheriae
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Causative agent of diptheria
G(+), Pleiomorphic, Cat(+), O2(+), non-sporeforming N' flora of skin & nasopharynx |
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Corynebacterium diptheriae
(Major virulence factor) |
Toxin genes carried on bacteriophage, β-Tox
Expression controlled by Fe availability via DtxR:(↓Host Fe → ↓DtxR action → ↑Toxin) Inhibit protein syn: Cytotoxin Classic AB subunit exotoxin: A(ADP-ribosylase) |
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Corynebacterium diptheriae
(Pathogenesis) |
Reservoir: human N' flora
Transmission: aerosol Colonize: URT mucosal surface Local damage & inflammatory response |
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Corynebacterium diptheriae
(Mortality) |
I. Mechanical airway obstruction
II. Systemic toxemia (myocarditis or paralysis) |
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Corynebacterium diptheriae
(Dx, Tx, & Pvn) |
Dx: throat culture on selective medium (tellurite agar)
Tx: 1° α-toxin, 2° α-biotics Pvn: DPT vaccine (toxoid) |
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Clostridium tetani
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Causative agent of tetanus
"lockjaw" G(+) rods, spore-forming, Motile, extremely O2 sensitive |
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Clostridium tetani
(Major virulence factor) |
Tetanospasmin
AB Subunit protein exotoxin |
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Clostridium tetani
(Tetanospasmin A & B subunits) |
B: Binds to gangliosides on CNS neurons
A: Zinc-dependent blocks release of inhibitory neurotransmitters; i.e., spastic paralysis |
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Clostridium tetani
(Pathogenesis) |
Reservoir: H20, soil, N' GI flora
Transmission: injection of spores into deep wound Systemic spread via nerve fibers, CNS, or bloodstream |
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Clostridium tetani
(Mortality) |
respiratory failure 15-60% fatal w/o treatment
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Clostridium tetani
(Dx;, Tx;, Pvn:) |
Dx: clinical presentation
Tx: 1° α-toxin (HTIG) 2° valium, respiratory asst., α-biotics Pvn: DPT toxoid vaccination |
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Clostridium botulinum
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"botox"
Very long rods, slightly alkaline, strict anaerobe |
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Botulinum toxin
(Action) |
Neuron-muscle cell synapse
blocks release of ACH leading to flaccid paralysis |
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Botulism
(4 types) |
Foodborne: (ingest pre-formed toxin) 6-36 hours
Infant: susceptible to those who harbor within their GI "floppy baby syndrome" Wound: infection Therapeutic: migraines, cosmetic, spasm, sweating disorders |
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Botulism
(Tx) |
Non-transmittable
Tx: 1° α-toxin (early admin.) α-biotics not helpful as organism need not be present Mortality: 10-20% |
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Vibrio cholerae
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Causative agent of cholera
Curved, G(-) rods, Mac Conkey growth, polar flagella O-Ag (outermost part of LPS) |
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Vibrio cholerae
(Virulence factor) |
Flagella, adhesins (TCP Type IV pili), hemagglutinin, colonization factor, neuraminidase
AB subunit protein exotoxin |
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Vibrio cholerae
(AB subunit) |
B: binds to GM1 ganglioside at brush border of epithelial cells of small intestine
A: ADP-ribosyl-transferase Alters G-protein activation: ↛cAMP → ↑H2O/Cl- excretion ↓Na+ re-absorb. Explosive hypermotility and copious watery diarrhea |
