Microbiology Quiz 7

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Microbiology Quiz 7
2010-07-06 00:59:44
SCC microbiology

Disease entry, ect.
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  1. Pathogen
    Disease causing microorganism
  2. Pathogenesis
    Development of disease
  3. Pathogenicity
    Ability to cause disease by evasion (escaping or protecting) from the host defenses
  4. Disease
    An abnormal state in which the body is not functioning normally
  5. INfectious disease
    Disease caused by a pathogen
  6. Etiology
    Study of the cause of a disease
  7. Etiological agent
    Agent causing a disease
  8. Transient microbiota
    May be present for days, weeks, months, and then disappear
  9. Resident microbiota
    Permanently colonize the host; is normal; doesnt cause disease in healthy individual
  10. Opportunistic pathoens
    Microbes don't cause any disease in healthy individual, but under other conditions
  11. Microbial antagonism
    Competition among microbes (observed b/w normal microbiota and pathogens) for common factors required for growth
  12. Normal microbiota inhibits growth of pathogen in the body by
    1. Reducing avaliability of nutrients/ growth factors2. Occupying receptors on host tissue3. Changing pH/ O2 Concentrations4. Producing toxins for pathogens
  13. Infection
    Presence of pathogen in body when it is normally not there
  14. Pathogenesis (4 stages)
    1. Entry of pathogen in teh body (infection)2. Adhesion of pathogen to host tissue3. Survival or pathogen against hot defense and invasion: virulence and virulent factors4. Development of diease
  15. Mucous membrane
    Location: Respiratory tract, urogenital tract, conjuntiva of eye, GI tract
  16. Skin (as portal of entry)
    2nd most common portalentry through pore, hair follicle, digesting keratin layer of skin w/ enzymes, burrow in skin (some helminths)
  17. Placental (portal of entry)
    Some viruses (HIV)Some bacteria, some protozoa Check mother's antibodies to seeSome infection --> mental retardation, miscarriage
  18. Parenteral route of entry
    Direct entry of pathogen in teh blood or deep in the tissueThrough cuts/ wounds, damaged physical barrier, contaminated blood transfusion, contaminated needles, bites of insects/ animals
  19. Virulence of a pathogen
    Strength of a pathogen, ability for it to escape from host defenses
  20. ID50 value
    the number of pathogens required to infect 50 percent of test population, lower value= more virulent
  21. Virulent adhesion factors
    Attachment of pathogen to the receptors of host tissue
  22. Coagulase
    Forms blood clots (prevents bacteria from host defenses)
  23. Kinases
    Dissolves blood clots (invasion/ spread of pathogen inside the body)
  24. Collagenase
    Dissolves collagen (helps bacteria invasde)
  25. IgA proteases
    Immunoglobulin A (antibodies) Help recognize pathogen. Proteases dissolve protein (destroys IgA antibody) mechanism for some pathogens to escape the immune system (protection)
  26. Keratinase
    Dissolves keratin (invasion)
  27. Hyaluronidase
    Hyauronic acid helps epithelial cells stick together; this enzyme destroys these cells and helps in invasion
  28. Toxigenicity
    Ability of microbe to produce toxin
  29. Exotoxin
    Produce inside mostly gram positive bacteria s part of their growth and metabolism. Secreted/ release followed lysis into surronding medium.
  30. Endotoxin
    part of outer portion of the cells wall (lipid A) of GM- bacteria. They are liberated when the bacteria die and the cell wall breaks apart (lysis of cell wall)
  31. Bacterial source (exo/endotoxin)
    Exo- Gram Positive Endo- Gram negative
  32. Chemical nature (endo/exo toxin)
    Endo- Lipid A)
  33. Heat stability (exo/endotoxin)
    Exo- heat labile (less stable, easily destroyed by heat) Endo- heat stable
  34. Fever producing toxin
    Endotoxins (pyrogen)
  35. Potency (toxicity) and LD value of endo exo toxins
    Exo- very high LD 50, endo- ow lethal dose; potency of toxic is inversely porportional to LOD50