Microbio Lecture 16
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- How to avoid food intoxication or infection: (4 things you should do)
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1. wash your hands with soap
2. separate cutting boards for meat vs. vegetables
3. cook meat till internal temp is 160-165 degrees F
4. put food in fridge to prevent bacterial growth - What is an intoxication?
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-bacteria make toxin
- toxins ingested with food or water
- short incubation time (1-3 hours) - What is an infection?
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- live bacteria ingested with food or water
- bacteria grow inside (intestines, etc)
- long incubation time (1-3 days) - Causative agent of Botulism?
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- Clostridium botulinum, G+, anaerobic spore former
- spores found normally in human or animal intestines - Transmission of Botulism?
- - in anaerobic environments
- Pathogenicity of Botulism?
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- spores germinate in anaerobic environment
- leads to growth of vegetative cells and production of botulism toxin (900 kD)
- Toxin blocks release of acetylcholine - Symptoms of Botulism?
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toxin in bloodstream lethal:
slurred speech, flaccid paralysis, difficulty swallowing, respiratory paralysis - Treatment and prevention of Botulism:
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antitoxin; prevent by heat foods to 90 degrees celsius for 10 minutes
NO HONEY FOR INFANTS
WOUND Botulism - Botox blocks what?
- Acetylcholine from nerve cells
- Botox can be used for what? (3)
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Strabismus: crosseyed
Blepharospasm: clenched eyelids
Spasticity: multiple sclerosis - Staphylococcus aureus causes what? What is the key reservoirs? Characteristics?
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- causes staphylococcal food poisoning
- G+ cocci, salt tolerant
- key reservoir is nose and skin - Transmission of Staphylococcus aureus?
- meats, fish dairy products via sneezing or boils or abscesses
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Pathogenicity of Staphylococcal Food Poisoning?
Incubation period? -
- heat resistant enterotoxin
- binds nerves in intestine, causes brain to send signal for vomiting and intestinal water secretion (diarrhea)
- incubation period very short 1-6 hours - Treatment of Staph. food poisoning
- No treatment; immune system takes care of it
- Causative agent of Salmonellosis?
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- hundreds of serotypes of Salmonella
i.e. S. typhimurium, heidelberg, newport, enteritidis
- G- rods - Transmission of Salmonellosis?
- poultry, eggs (in ovaries of hens), cutting boards, iguanas and easter chicks
- Pathogenicity of Salmonellosis?
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- incubation period of 1-3 days
- inflammatory response to infection increases fluid secretion - Symptoms of Salmonellosis?
- nausea, fever, vomiting, diarrhea, abdominal cramps
- Treatment of Salmonellosis?
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none- bacteria eaten by macrophages
if serious, treat with ciprofloxacin - Causative agent of Typhoid fever?
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Salmonella typhi, G- rod
- lives in sewage, water and food
- can live in stomach acid
- VERY HARDY - Transmission of Typhoid fever (Five F's)
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fingers, food, flies, feces, fomites
Typhoid mary - Pathogenicity of Typhoid fever?
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only pathogenic to humans
invades tissues in small intestines cutting up the intestines (ulcers) - Symptoms of Typhoid fever?
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ulcers, bloody stools (dysentery);
- lead to blood invasion and go to brain that causes delerium (typhos)
- rose spots on abdomen (hemorrhaging) - Treatment of Typhoid fever?
- Chloramphenicol, some become carriers and need gall bladder surgery to remove it
- Causative agent of cholera?
- Vibrio cholera, G-, curved rod
- Transmission of Cholera?
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- Water or food contaminated with feces
- raw oysters - Symptoms of Cholera?
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- diarrhea (1L/hour)
- dehydration, cramps
- blood thickens, shock/coma
- 70% mortality - Pathogenicity of Cholera?
- enterotoxin stimulates fluid loss
- Treatment of Cholera?
- antibiotics and ORS (oral rehydration solution of electrolytes and glucose)
- What does ORS stand for?
- Oral rehydration solution like Gatorade and Pedialyte
- Transmission of E. Coli diarrheas?
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- ground meat
- inadequately washed fruits and veggies
- low infectious dose = lots of toxins produced - Pathogenicity of E. Coli diarrheas?
- dehydration, salt imbalance by various mechanisms: enterotoxin and enteroinvasive (penetration of intestinal epithelium)
- Enteroinvasive mechanism of E. Coli bacteria leads to these types of diarrheas: (2)
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Infant diarrhea: caused by both enterotoxic and enteroinvasive
Traveler's diarrhea- E. Coli adhere with pili and produce enterotoxin - What does O157:H7 mean?
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Specific type of E. Coli
O means cell wall antigen
H means flagellar antigen - Symptoms of E.Coli?
- Diarrhea and other things...
- Treatment and Prevention of E.Coli diarrheas?
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- antibiotics and rehydration
- prevention by cooking meat at 160 C - Complications of E. Coli diarrheas?
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- hemorrhagic colitis if confined to large intestine: inflammation of large intestine
- hemolytic uremic syndrome if spread to kidneys - kidney failure, seizure, coma, heart attack - Causative agent of Peptic Ulcer Disease?
- Helicobacter pylori
- Transmission of Peptic Ulcer Disease?
- contaminated food and water, houseflies in feces
- Pathogenicity of Peptic Ulcer Disease?
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- gets through mucus of stomach lining and attaches to stomach wall
- secretes urease to digest urea, neutralize stomach acid therefore higher pH
- bacteria secrete toxins to make ulcers - Symptoms of Peptic Ulcer Disease?
- Ulcers
- Treatment of Peptic Ulcer Disease?
- Biaxin (clarithromycin), Prilosec (omeprazole), Tetracycline
- Diagnosis of Peptic ulcer disease?
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Urea breath test:
- labeled urea given to patient, urease breaks up urea into NH3 and CO2(labeled), exhalation has labeled CO2