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38 Cards in this Set
- Front
- Back
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Structure of Digestive system
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GI tract: mouth, pharynx, esophagus, stomach, small and large intestine
Accessory: salivary glands, liver, gall bladder, pancreas |
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Dental caries mainly caused by what organism?
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main cause is Streptococcus mutans
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How does S. mutans initiate formation of plaque (biofilm)?
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converts sucrose to dextran, a sticky polysaccharide (froms glycocalyx)
glycocalyx enables attachment to tooth enamel other bacterial spp. adheres to glycocalyx via fimbriae forming biofilm if not removed, may harden into calculus (tartar) |
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In caries, what causes decalcification of enamel?
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lactic acid fermentation of sugars
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Periodontal disease may lead to...
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sepsis and heart damage
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Bacterial diseases of GI tract
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Foodborne intoxications (food poisoning), foodborne and waterborne infections
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Foodborne intoxications
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noninflammatory gastroenteritis
brief incubation, period, quick resolution |
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Staphylococcal food poisoning caused by
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Staphylococcus aureus
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When is food usually contaminated with S. aureus?
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during preperation
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What type of exotoxin is produced by S. aureus?
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heat-stable enterotoxin
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How long does it take for symptoms to appear after ingesting toxin? What are the symptoms?
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1 to 6 hours; cramps, vomiting, diarrhea
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Clostridial food poisoning caused by
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Clostridium perfringens
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C. perfringens produces endospores? Is it anaerobic or aerobic?
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endospore forming obligate anaerobe
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Where can we find C. perfringens?
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dwells in soils and GI tract
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Will endospores of C. perfringens survive cooking?
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They may still germinate
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C. perfringens produces what kind of toxin?
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heat labile enterotoxin
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Symptoms appear within...and they are...
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8 to 24 hours, cramps and diarrhea only
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Botulism caused by
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Clostridium botulinum (very similar to C. perfringens in that it is also endospore forming, obligate anaerobe found in soil and GI tract)
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Where do endospores germinate for C. botulinum?
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anaerobic environment like cans
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What kind of toxin is botulism toxin? What does it do?
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neurotoxin that inhibits acetylcholine release (respiratory failure to due to paralysis)
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Symptoms appear within...and cause...
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12 to 48 hours; blurred vision, slurred speach, difficulty swallowing, paralysis follows, death due to respiratory failure
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Infant botulism characteristics
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results from ingestion of endospores, infants less than a year old shouldn't eat honey
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Foodborne and waterborne infections have a longer or shorter incubation period than intoxications?
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longer
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Inflammatory gastroenteritis characterized by...
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diarrhea and/or vomiting, often fever, no blood in stool
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Cholera caused by
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Vibrio cholarae
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How do people get cholera usually?
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Raw oysters and water
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Why does cholera require a high infectious dose?
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V. cholarae has a low resistance to acidity
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What does cholera toxin cause?
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Causes loss of water and electrolytes
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Cholera toxin is characterized by what kind of stools?
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"rice-water stool"
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How does cholera lead to death?
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shock and coma from water loss
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How do you treat cholera?
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Water, electrolytes, and antibiotics
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Other Vibrio species causing cholera-like illness
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V. parahaemolyticus and V. vulnifians (infection from raw shellfish)
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Escherichia Coli common form is
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Enterotoxigenic E. coli (ETEC) (most common cause of bacterial traveler's diarrhea)
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How is it transmitted :P
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via fecal-oral route
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Produces 2 enterotoxins
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one resembles cholera toxin, lasts 3 to 7 days
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Who is susceptible to Clostridium difficile (C. diff.)
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Elderly and long-term antibiotics users
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Where are the endospores of C. diff. usually acquired?
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Health care facility (nosocomial infection) - long lasting infection may result
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Treatment of C. diff.?
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Stop using antibiotics, fecal transplants
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