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MIC101 Lecture 9

patience.almazan English 96 cards

Cards in this deck (96)

  1. 1What is the title of Lecture 9?Microbial Mechanisms of Pathogenicity
  2. 2How do microbes cause disease?Gain entry to host, attach to & invade specific cells &/or tissues within the host, evade host defenses, obtain nutrients from the host, exit the host
  3. 3How do microbes get into a host?3 categories of portals of entry: Mucous membranes, skin, & parenteral routes
  4. 4What occurs in the parenteral routes?deposition directly into tissues beneath the skin & mucous membranes
  5. 5Where are mucous membranes found?Respiratory tract, gastrointestinal tract, genitourinary tract
  6. 6What is the most favorable portal of entry?Respiratory tract
  7. 7Describe the respiratory tractMost favorable portal of entry, pathogens can be found on droplets of moisture & dust particles
  8. 8Which pathogens use the respiratory tract?cold virus, bacteria/viruses that cause pneumonia, mycobacterium tuberculosis, influenza virus, measles virus, smallpox virus
  9. 9What is the 2nd most favorable portal of entry?Gastrointestinal tract
  10. 10What pathogens use the GI tract?Salmonella, Shigella, Escherichia, Hapatitis virus, Giardia
  11. 11Are UTI's more common in men or women?women
  12. 12What causes major problems in hospitals & clinical settings?Infections of the Genitourinary Tract
  13. 13How are diseases of the reproductive tract usually transmitted?sexually
  14. 14What pathogens use the genitourinary tract?Chlamydia, HIV, Herpes virus
  15. 15Describe Skinlargest organ in the body, large surface area provides vast area where pathogens may enter the body, many microorganisms reside on the skin, provides an impermeable barrier to most microbes
  16. 16What provides an impermeable barrier to most microbes?Skin
  17. 17Describe the Parenteral Routerefers to breaks in the skin which permit entry of microorganisms (injections, cuts, wounds, surgical procedures & insect bites)
  18. 18What are injections, cuts, wounds, surgical procedures & insect bites an example of?The Parenteral Route
  19. 19What do pathogens use to stay in the host?use structures to attach to the surface of cells or tissues such as capsules, adhesins, & fimbriae
  20. 20What are capsules, adhesins, & fimbriae examples of?structures that pathogens use to attached to the surface of cells or tissues
  21. 21Describe Biofilma group of microorganisms in which cells stick to each other on a surface, example of adherence is the plaque found on teeth
  22. 22What are a group of microorganisms in which cells stick to each other on a surfaceBiofilms
  23. 23What is ID50?(Infectious dose 50%)= the # organisms req'd for 50% of the host population to show signs of infection
  24. 24the # organisms req'd for 50% of the host population to show signs of infectionID50
  25. 25What is LD50?(lethal dose 50%)=the # organisms re'd to kill 50% of a host population
  26. 26What is the # of organisms req'd to kill 50% of a host populationLD50
  27. 27How can pathogens defeat host defenses?Using passive defenses & Active Defenses
  28. 28What are passive defenses?built-in structures found on the pathogens such as capsule & cell wall components
  29. 29Can you describe the capsuleprevents binding of the complement protein C3b
  30. 30What does C3b do?binds to microbial cell surfaces & aids in opsonization of the microbe by macrophages
  31. 31What are cell wall components used to defeat host defenses?M proteins (Streptococcus pyogenes) which inactivates C3b & Mycolic acid (Mycobacterium tuberculosis) which protects bacteria against antiseptics, disinfectants, & antibiotics
  32. 32What are capsule & cell wall components an example of?Passive defenses that pathogens use to defeat host defenses
  33. 33What are M proteins & Mycolic acid examples of?Cell wall components that pathogens use to defeat host defenses.
  34. 34Describe Active defenses that pathogens use to defeat host defensesattacking the host
  35. 35Give an example of active defenses that pathogens use to defeat host defenses.Bacterial Defensive Enzymes
  36. 36What do active bacterial defenses involve?producing extracellular enzymes
  37. 37List the Bacterial Defensive EnzymesLuekocidins, Hemolysins, Coagulase, Kinases, Hyaluronidase & Collagenase
  38. 38What do Leukocidins do?destroy white blood cells (neutrophils, macrophages, & lymphocytes)
  39. 39What do Hemolysins do?they are membrane-damaging toxins that attack red & white blood cells
  40. 40What does Coagulase do?cause the formation of fibrin clots
  41. 41What do Kinases do?Break down fibrin & destroy clots
  42. 42What do Hyaluronidase & Collagenase?break down connective tissue & collagen
  43. 43What breaks down connective tissue & collagen?Hyaluronidase & collagenase
  44. 44What breaks down fibrin & destroys clotsKinases
  45. 45What are membrane-damaging toxins that attack red & white blood cellsHemolysins
  46. 46What destroys white blood cells (neutrophils, macrophages & lymphocytes)Leukocidins
  47. 47How do Bacterial Defensive Enzymes work?Pathogens produce coagulase, blood clot forms around pathogens, pathogens produce kinase, dissolving clot & releasing bacteria, invasive pathogens reach epithelial surface, pathogens produce hyaluronidase, pathogens now able to invade deeper tissues
  48. 48How do pathogens hide from the host defense?They get inside the host. Viruses are obligate intracellular pathogens & can easily enter host cells. Bacteria uses the host cell cytoskeleton (microtubules & microfilaments) to get into & move around a host cell.
  49. 49What part of the host cell do bacteria use to get into & move around a host cell?cytoskeleton
  50. 50How can bacteria damage the host cell?Direct Damage: destroying the host cells/tissues using siderophores to sequester iron from the host. Indirect Damage: involves systemic infection as a result of toxin production by the pathogen.
  51. 51What is it called when a pathogen destroys host cells or tissues using siderophores?Direct Damage
  52. 52What is it called when pathogens produce toxin to create a systemic infection in the host?Indirect Damage
  53. 53What is required for growth of most pathogens?Iron
  54. 54Why is the concentration of free iron in the human body low?Because it is bound to iron-transport proteins, such as lactoferrin & transferrin
  55. 55What are siderophoresBacterial iron-binding proteins
  56. 56What are the two types of Bacterial Toxins?Exotoxins & Endotoxins
  57. 57What are exotoxins?proteins produced inside pathogenic bacteria, most commonly gram-positive bacteria, as part of their growth & metabolism. The exotoxins are then secreted or released into the surrounding medium following lysis.
  58. 58What are endotoxins?The lipid portions of lipopolysaccharides (LPSs) that are part of the outer membrane of the cell wall of gram-negative bacteria. The endotoxins are liberated when the bacteria die and the cell wall breaks apart.
  59. 59What are proteins produced inside pathogenic bacteria that are secreted or released into the surrounding medium following lysis?Exotoxins
  60. 60What are the lipid portions of lipopolysaccharides that are part of the outer membrane of the cell wall of gram-negtaive bacteria?Endotoxins
  61. 61What are Exotoxins usually produced as?pro-enzymes
  62. 62What are the 3 types of exotoxins?Cyotoxins, Neurotoxins, & Enterotoxins
  63. 63What do cyotoxins do?kill cells
  64. 64What do Neurotoxins do?interfere with neurological signaling
  65. 65What do Enterotoxins do?affect the lining of the digestive system
  66. 66What are the 5 Exotoxins we are learning about?Anthrax, Botulinum, Tetanus, Diphtheria, & Vibrio
  67. 67What does Anthrax do?increases vascular permeability
  68. 68What organisms produces Anthrax?Bacillus anthracis
  69. 69What are the symptoms of Anthrax?Hemorrhage & pulmonary edema
  70. 70What does Botulinum do?blocks release of acetylcholine
  71. 71What organism produces Botulinum?Clostridium botulinum
  72. 72What are the symptoms of Botulinum?respiratory paralysis
  73. 73What does tetanus do?inhibits motor-neuron antagonists
  74. 74What organism produces Tetanus?Clostridium tetani
  75. 75What symptoms does Tetanus cause?Violent skeletal muscle spasms, respiratory failure
  76. 76What does Diphtheria do?Inhibits protein synthesis
  77. 77What organism produces Diphtheria?Corynebacterium diphtheriae
  78. 78What symptoms does Diphtheria cause?Heart damage, possible death weeks after apparent recovery
  79. 79What does Vibrio do?causes excessive loss of water & electrolytes
  80. 80What organism produces Vibrio?Vibrio cholerae
  81. 81What symptoms does Vibrio cause?Severe diarrhea; death can occur within hours
  82. 82What is Bacillus anthracis?a Gram-positive spore-forming rod commonly found in pastures
  83. 83What does Anthrax Toxin consist of?Edema factor, Lethal factor, Protective antigen
  84. 84What does the Edema factor of Anthrax do?increases cAMP levels
  85. 85What does the Lethal factor of Anthrax do?inhibits MAPK activity
  86. 86What is the protective antigen of Anthrax?transmembrane factor
  87. 87What is 1 characteristic of Anthrax toxin?Increases vascular permeability in host cells
  88. 88What is inhalation anthrax?fulminate pneumonia leading to respiratory failure & death
  89. 89How does Corynebacterium diphtheriae enter/exit the host? What does it cause?enters by inhalation, exists by respiratory secretions. Causes diphtheria.
  90. 90Where does Corynebacterium diphtheriae grow & release toxin? What does it cause?Grows/releases toxin in the throat. Causes diptheria.
  91. 91What does diphtheria toxin do (in detail)?destroys local cells, leading to the formation of a pseudomembrane, is absorbed by the blood & carried to the heart, nervous system & other organs. It also inhibits protein synthesis in the host.
  92. 92In what form is Diptheria toxin released?in an inactive form
  93. 93What happens to Diptheria toxin once it is released in an inactive form?It is cleaved extracellularly into 2 chains, A & B, which remain joined by a disulfide bond. B attaches to the specific receptor on host cells. A inactivates EF-2 (elongation factor-2) by ADP-ribosylation. Protein synthesis ceases & the cell dies.
  94. 94What is Clostridium botulinum? What does it cause?anaerobic, Gram-positive, spore-forming, rod-shaped bacteria that causes botulism
  95. 95When do symptoms of Botulism begin?12-36 hours after ingestion of improperly canned food, toxin is absorbed by the small intestine, & can circulate in the bloodstream
  96. 96What are symptoms of Botulism?Dizziness, dry mouth, blurred or double vision, abdominal symptoms including pain, nausea, vomiting, diarrhea

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Flashcards on MIC101 Lecture 9, created by patience.almazan on 05/05/2015.
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