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What is the typical route of infection for Clostridium Botulinum?
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Food intoxication
ingestion of PRE-FORMED toxin - not spore |
Where is Clostridium Botulinum usually found?
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Canned foods with alkaline pH
Spores germinate in anaerobic environment Inhaled Clostridium Botulinum is a biological warfare Wound infections RARELY occur - stomach acid kills it |
How many virulence factors for Clostridium Botulinum?
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1. Botulinum toxin
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Features of botulinum toxin in Clostridium Botulinum
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Exotoxin
Heat labile neurotoxin Similar to tetanospasmin - AB subunit Surrounded by proteins to resist destruction in GI tract 7 antigenically distinct forms - 4 (A,B,E,F) cause human disease lethal dose <1microgram |
What are the antigenically distinct forms that cause human disease?
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A,B,E,F
Type B - common in eastern US Type A - botulinum, used in Botox |
How is botulinum toxin internalized?
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Endocytosis - same way as tetanospasmin
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Where does the botulinum toxin stay?
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Neuromuscular junctions
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Where is the toxin absorbed?
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Absorbed from small intestine to blood
Travels to neuromuscular junction |
How long is the incubation period?
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18-96 hours
Depends on how much toxin you eat/ingest |
Symptoms
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Weakness
Dizziness Blurred vision dilated pupils double vision dry mouth constipation urinary retention |
What kind of paralysis occurs?
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Extensive paralysis of voluntary muscle
Flaccid paralysis |
Recovery and survival of Clostridium Botulinum
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Recover- ability to regenerate new nerve ending without toxin
Surviving doesnt provide immunity- amount so small no antibody response Mortality - 10% with treatment |
Infant botulism
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Up to 12 years old
Less than 100 cases/year Spores in honey or dust/dirt Babies dont have enough acidity to kill spores Germinate in GI tract and produce toxin |
Symptoms of infant botulism
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Lethargy
Constipation Poor muscle tone Lead to respiratory arrest SIDS may be related |
Treatment of Clostridium Botulinum
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Antitoxin for adults comes from horses
Antotoxin for infant comes from Human Botulism Immunoglobulin - BIG Neutralizes free toxin Supportice therapy - ventalator Metronidazole or penicillin??? |