Microbiology Ch 25

  1. Normal Microbiota
    • -millions of bacteria per ml of saliva
    • -large numbers in large intestine
    • -100 billion bacteria per gram of feces 
  2. Defenses of the human digestive system
    • -Stomach; acidic 
    • -small intestines; paneth cells
    •         Defensins and lysozyme  
  3. What is Dental Caries?
    It is Tooth Decay
  4. Stages of Dental Caries
    • -S.mutans attaches to proteins on tooth
    • -Eat sucrose to produce dextran
    • -Bacteria accumulate on dextran=dental plaque
    • -Ferment sugar to produce lactic acid
    •    = cavity  
  5. Disease of Lower Digestive System

    • -infection: growth of a pathogen
    •       *incubation is from 12 hours to 2 weeks
    •       *fever
    • -Intoxication: ingestion of toxin
    •      *symptoms appear 1 to 48 hours after ingestion
    • -Gastroenteritis: Diarrhea, dysentery
    • -Treatment: Oral rehydration therapy 
  6. Staphylococcal food poisoning
    Pathogen: Staphyloccus aureus

    Symptoms: Nausea, vomiting, and diarrhea

    Intoxication/infection: intoxication, enterotoxin (superantigen)

    Diagnosis: phage typing

    Treatment: none 
  7. Events in Staphylococcal Food poisoning
    1-Food containing protein is cooked (bacteria usually killed)

    2-Then food is contaminated by worker with staphyloocci on hands (competing bacteria have been eliminated)

    3-Food is left at room temperature. Organisms incubatee in food (temperature abuse) long enough to form and release toxins. (Reheating will eliminate staphylococi but not the toxins).

    4-Food containing toxins is eaten

    5- In one to six hours, staphylococcal intoxication occurs.  
  8. shigellosis (Bacillary Dysentery) 

    Pathogen: Shigella spp

    Symptoms: tissue damage and dysentery

    Intoxication/infection: Infection endotoxin and shiga exotoxin

    Diagnosis: isolation of bacteria

    Treatment: Quinolones  
  9. Salmonellosis 

    characteristics of disease 
    • Pathogen: Salmonella enterica
    • Symptoms: Nausea and diarrhea
    • Intoxication/infection: infection endotoxin
    • Diagnosis: Isolation of bacteria; serotyping
    • Treatment: oral rehydration  
  10. Typhoid Fever

    Characteristics of disease  
    • Pathogen: S.typhi
    • Symptoms: High fever, significant mortality
    • Intoxication/infection: Infection endotoxin
    • Diagnosis: isolation of bacteria; serotyping
    • Treatment: Quinolones; cepholosporins  
  11. Typhoid Fever
    • -Caused by Salmonella tyhpi
    • -Bacteria spread throughout body in phagocytes
    • -1-3% of recovered patients become chronic carriers

  12. Vibrios
    • -Cholera
    •     *Vibrio cholerae serotypes that produce choler toxin
    •     * Toxin causes host cells to secret Cl-, HCO-, and water

    • -Noncholera vibrios
    •     -Usually from contamintd crustaceans or mollusks
    •     -V.cholerae serotypes other than O:1,  O:139, eltor
    •     -V.parahaemolyticus
    •     -V.vulnificus 
  13. Escherichia coli Gastroenteritis 
    -Pathogenic E.Coli

    •     * attach to intestinal cells with fimbriae
    •     *Produces toxins
    •     * May aggregate  
  14. Campylobacter Gastroenteritis

    • Pathogen: campylobacter jejuni
    • Symptoms: Fever, abdominal pain, diarrhea
    • Intoxication/infection: infection
    • Diagnosis: Isolate Bacteria
    • Reservoir: chickens, cow's milk  
  15. Helicobater Peptic Ulcer Disease
    • Pathogen: Helicobacter pylori
    • Symptoms: peptic ulcers
    • Intoxication/infection: infection
    • Diagnosis: Urea breath, bacterial culture
    • Treatment: antimicrobial drugs  
  16. Hepatitis 
    • -An inflammation of the liver
    • -Caused by at least 5 different viruses
    • -may result from drug or chemical toxicity, EB virus, CMV, or the hepatitis viruses 
  17. Giardiasis
    • pathogen: Giardia lamblia
    • symptoms: protozoan adheres to intestinal wall, diarrhea
    • Reservoir: water or mammals
    • Diagnosis: FA test
    • treatment: metronidazole; quinacrine  
  18. Cryptosporidiosis
    • Pathogen: Cryptosporidium hominis
    • Symptoms: self-limiting diarrhea; may be life-threatening in immunosuppressed people
    • Reservoir: cattle, water
    • Diagnosis: Acid-fast stain; FA; ELISA
    • treatment: oral rehydration
  19. Cyclospora Diarrheal Infection
    • Pathogen: Cyclospora cayetanensis
    • Symptoms: Watery diarrhea
    • Reservoir: humans; birds
    • Diagnosis: Microscopy
    • Treatment: trimethoprim and sulfamethoxazole 
  20. Amoebic Dysentery
    • Pathogen: Entamoeba histolytica
    • Symptoms: Abscesses; significant mortality rate
    • Reservoir: humans
    • Diagnosis: microscopy; serology
    • treatment: Metronidazole  
Card Set
Microbiology Ch 25
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