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28 Cards in this Set
- Front
- Back
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Name the 2 spore-forming, gram positive rods
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Bacilus and Clostridium
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How can you differentiate Bacillus and Clostridium?
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Bacillus - Aerobic, Clostridium = Anareobic (in an air tight CLOSet)
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Name the 2 pathogenic aerobic spore forming rods
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B. anthracis, B. cereus
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What is an unusual component of the B. anthracis capsule?
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Protein (poly-D-glutamic acid)
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What disease is caused by B. anthracis spores?
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Anthrax, from infected animal products (e.g., goat hair)
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What plasmid contain the virulence factors in B. anthracis?
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pXO1 and pXO2
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What activates pXO1 and pXO2?
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heat, CO2, serum proteins
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Organs succeptible to B. anthracis infection
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skin (most common), lungs, GI
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Result of B. arnthrcis skin infection
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localized necrosis,painless black lesion (malignant pustule) with ring of edema
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Treatment for B. anthracis skin infection
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penicillin
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What 3 toxins are encoded on the pXO1 plasmid of B. anthracis?
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1) Edema Factor (EF): inc. cAMP, impairs neutros, massive edema
2) Protective Antigen (PA): puts EF into phagocytes 3) Lethal Factor (LF): zinc metalloprotease, inactives protein kinase, cause macro to release TNF-a and IL-1B |
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What is the purpose of the pXO2 plasmid?
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Encodes 3 genes for the synthesis of the poly-glutamyl capsule (inhib. phago)
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Treatment for systemic B. anthracis infection
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ciprofloxacin or doxycycline
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B. cereus secretes what 2 enterotoxins that cause food poisoning?
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1) heat labile toxin: like cholera toxin
2) heat stable toxin: like Staph. aureus food poisoning Both cause diarrhea, ab pain, nausea |
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Do you treat B. cereus food poisoning with antibiotics?
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NO!!! Be Serious! The symptoms are a result of an pre-formed enterotoxin.
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Name 4 diseases caused by Clostridium
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1) botulism
2) tetanus 3) gas gangrene 4) pseudomembranous colitis |
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Action of Clostridium botulinim
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- Bacteria release a lethal neurotoxin
- blocks release of ACh - flaccid paralysis - 3 types: Adult, Infant, Wound |
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Describe adult botulism
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- From smoked fish or canned veges not cooked enough
- adults ingest NEUROTOXIN - diplopia, dysphagia, respiratory paralysis - Tx: antitoxin |
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Describe infant botulism
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- From honey
- infants ingest SPORES - "floppy baby" - Tx: IVIG |
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Describe wound botulism
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- Spores enter wound
- presents similar to adult form - Tx: debridement, anti-toxin and antibiotics |
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Name the exotoxin released by Clostridium tetani
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tetanospasmin
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How does tetanospasmin causes tetanus?
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- prevent release of inhibitory neurotransmitters (GABA and glycine) from Renshaw cells
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Presentation of tetanus
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- lockjaw
- grotesque grin (risus sardonicus) |
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How do you treat tetanus in the unvaccinated?
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1) neutralize toxin (IVIG)
2) give booster 3) excise wound 4) penicillin 5) support + muscle relaxers |
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What bacteria causes gas gangrene?
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Clostridium perfringens
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What are the 3 classes of C. perfringens infection?
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1) Cellulitis/wound infection: crepitus in skin
2) Clostridial myonecrosis: gas pockets in muscle from degrade 3) Diarrheal: food poisoning |
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What bacteria causes psuedo-membranous colitis?
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Clostridium difficile
- following broad spec. antibiotics - very "difficile" to give antibiotics - stool sample to confirm - kill with vanco or metronidazole |
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What is binary toxin CDT?
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- made by C. diff.
- 15 to 20 times more powerful |
