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9 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Bacteria cause disease by which two MECHANISMS?
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1) Toxin- mediated disease
2) Invasion and Inflammation |
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What is are 2 examples of TOXIN MEDIATED DISEASE?
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1) Botulism: caused by clostridial toxin, and you do not have to ingest the organism
2) Staphylococcus aureus enterotoxin: the most common food-borne diarrheal disease in the US |
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How do INVASION AND INFLAMMATION cause disease?
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Disease occurs via direct tissue invasion and then tissue damage occurs because of OVER- REACTIVE IMMUNE RESPONSE from the host.
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What are the pathogenic steps in establishing bacterial infections by ingesting toxin?
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1) Toxins preformed in food
2) Ingestion of microorganisms with adherence, colonization, and TOXIN FORMED IN GUT |
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What are two examples of TOXINS PREFORMED IN FOOD?
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1) Clostridium botulism, preformed in food, is ingested
2) S. aureus enterotoxin preformed in contaminated food (Disease can occur in the absense of the organism) |
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What are two examples of microorganisms that adhere, colonize, and form toxins in the gut?
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1) Infant botulism: organisms in the honey form toxins when it is in the gut because the lumen in anaerobic
2) Vibrio cholerae: intestinal colonization followed by secretion of cholera toxin |
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What are 4 general characteristics of CLOSTRIDIUM?
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1) OBLIGATE ANAEROBE
2) Location of spore in the bacterium may aid in species identification 3) CATALASE NEGATIVE 4) OXIDASE NEGATIVE |
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What are 4 species of CLOSTRIDIUM?
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1) C. botulinum: noninvasive, causing BOTULISM and can be an agent to of bioterrorism
2) C. tetani: generally noninvasive, causitive agent of TETANUS 3) C. difficile: noninvasive, secreted toxin causing pseudomembranous entercolitis (can cause DIARRHEA) 4) C. perfringens: VERY INVASIVE, CAUSES GANGRENE 5) C. septicum: invasice in MALIGNANCY 6) C. ramosum 7) other invasive clostridial species |
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What are 4 things that contribute to PATHOGENESIS of Clostridium?
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1) BOTULISM TOXIN: cause of flaccid paralysis
2) TETANUS TOXIN: causes of tetanus 3) EXOTOXINS A & B: cause of diarrhea in PSEUDOMEMBRANE COLITIS because of C. difficile 4) ALPHA TOXIN: lecithinase which is lysed in host cell membrane- - this is in combination with other enzymes as the cause of "gas gangrene" due to C. perfringens |
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