MIC 541-Lecture 20

  1. Mycobacteria characteristics:
    • Obligate Aerobes
    • Slender rod shaped
    • Non-motile
    • Non-sporulating
    • Ubiquitous organism that can be found in humans and animals
  2. Unique features of Mycoacteria
    • Acid Fast (Ziehl-Neelsen)
    • Cell wall lipid: mycolic acid
    • Resist acids, alkalis and germacide antibiotics
    • Pathogens = rough colonies
    • Grow and divide slowly
  3. Acid fast bacteria stain:
  4. non-acid fast bacteria stain:
  5. Term for Mycobacterium Tuberculum in acid fast smears is:
    Acid fast Bacilli
  6. Easier method (than acid fast staining) to screen for Mycobacteria:
    Auramine stain
  7. Auramine stained mycobacteria appear:
    Glowing yellow rods
  8. Infections of mycobacteria can often be seen where?
    Inside Macrophages in the lymph nodes
  9. Mycobacteria infect what type of immune cell
  10. Cord Factor characteristics:
    • Glycolipid
    • Inhibits migration of PMNs
    • Small quantiites are lethal in lab animals
    • abundant in virulent strains
    • absesnse= non-virulent
  11. Cord factor absesnse =
    non-virulent strain
  12. Cord factor is a:
    Glycolipid cell wall component
  13. Virulence factors for Mycobacteria
    • Clumpy in water/ether
    • Cord factor
  14. Gram stain of Mycobacteria
    Neither G+ or -
  15. Mycobacteria taxonomy is based on these characterisitics:
    • Colony morphology
    • Pigmentation
    • Growth Rate
  16. Characteristics of Mycobacteria in Group I
    • Photochromatic - only produce pigemented colonies in lighted conditions
    • Slow growth (greater than one week)
  17. Example of Group I mycobacteria
    Mycobacterium kansassi
  18. Mycobacterium kansassi pigmentation color
    yellow orange colonies
  19. Yellow oragnge colonies of mycobacterium indicated the genus and species:
    Mycobacterium kansassi
  20. Mycobacterium kansassi only produce pigment under what condition?
    Presence of light
  21. Mycobacterium kansassi growth rate is:
    slow, greater than one week
  22. Group II mycobacteria characteristics:
    • Slow growth rate (greater than 1 week)
    • Scotochromogenic - produce pigement in the absense of light
  23. Group II Mycobacteria example
    Mycobacterium scrofulaceum - produces red orange colonies
  24. Mycobacterium scrofulaceum produces colonie that are colored:
  25. red orange mycobacteria colonies indicate the species and genus of:
    Mycobacterium scrofulaceum
  26. Mycobacterium scrofulaceum has a gorwth rate that is:
    Slow, greater than one week
  27. Mycobacterium scrofulaceum is in Group:
  28. Mycobacterium kansassi is in the Group:
  29. Mycobacterium Group III characteristics:
    • Slow growth rate (greater than 1 week)
    • Non-pigmented
  30. Example of Group III Mycobacterium:
    Mycobacterium avium-intracellulare
  31. What color are teh colonies of Mycobacterium avium-intracellulare
    Buff colored
  32. Mycobacterium avium-intracellulare is a member of mycobacterium Group:
  33. Group IV Mycobacterium characteristics:
    Fast growth rates
  34. An example of Mycobacterium Group IV is:
    Mycobacterium Fortuitum-chelonae
  35. Mycobacterium Fortuitum-chelonae is a member of what mycobacterial Group:
  36. Mycobacterium fortuitum-chelonae is what color:
  37. Mycobacterium fotuitum-chelonae has a growth rate of:
    fast (less than one week)
  38. MOTT stands for:
    Mycobacterium other than M. Tuberculosis
  39. MOTT is a classification of what type of mycobacterium?
    Those other than M. tuberculosis
  40. Characteristics of the disease tuberculosis are:
    • Found worldwide
    • Communicable disease
    • Spread by droplet nuclei
    • Primary lesion-tubercle or lymph node lesion
    • Primary complex
    • Caseation/secondary lesion
  41. Tubercule foci are medically significant because they can:
    harbour bacteria for years until teh host immune defenses are comprimised.
  42. Droplet nuclei are transmitted through the:
  43. Droplet nuclei are created by
    speaking, singing, coughing of infecetd individual
  44. Droplet nuclei are transferred by contact (true/false)
  45. Droplet Nuclei land where:
    The Lungs
  46. Another term for Miliary tuberculosis is:
    Disseminated tuberculosis
  47. Disseminated/Miliary tuberculosis is different from normal tuberculosis in that:
    • The infection is not localized to the Lungs
    • Many organs are effected
  48. Miliary/disseminated tuberculosis can result from:
    Breaking of bacterial pockets into blood stream and traveling around the body.
  49. Previously exposed individuals (to M. Tuberculosis) develop what immune response:
    Delayed type hypersensitivity
  50. What is the basis for TB skin tests
    Delayed type hypersensitivity that develops after TB exposure.
  51. The immune response to TB is:
    Cell mediated immune reaction or T cell response
  52. The Mantoux test is for:
  53. The Mantoux test is administered where:
  54. The Mantoux skin test needs to incubate for:
    48-72 hours
  55. After receiving a Mantoux test, an induration of 0-5mm indicates:
    Negative for TB
  56. After receiving a Mantoux test, an induration of 5-9 mm indicates:
    Indeterminate previous TB
  57. After receiving a Mantoux test, an induration of 10mm or more indicates:
    Positive for TB
  58. A positive TB test can be determined by:
    An induration of greater than 10mm
  59. An indeterminate TB test is determined by:
    An induration of 5-9mm
  60. A negative TB test can be determined by:
    An induration of 0-5mm
  61. A TB test is also called
    A Mantoux test
  62. The Mantoux test divides the population into how many groups?
  63. Downfalls of Mantoux TB test:
    false positives due to allergic reaction
  64. The Mantoux test is performed by injecting:
  65. PPD stands for
    Purified Protein Dervivative
  66. Flase positive of Mantoux test can be verified or dismissed using what other test?
    Quantiferon Gold test
  67. Which test for Tb has the most specificity?
    Quantiferon Gold test
  68. Quantiferon Gold test detects:
    Release of IFN-g in whole blood when incubated with 2 synthetic peptides represnting proteins of TB
  69. A huge induration after a TB test indicates:
    Allergic reaction
  70. After seeing a huge induration after a PPD TB test, you should perform what other test?
    Quantiferon Gold test
  71. Which TB test detects INF-g:
    Quantiferon Gold test
  72. Treatment of TB is:
  73. TB treatment regimen last how many months:
  74. Treatment of TB in the first 2 months is with:
    isoniazid, rifampin, pyrazinamide
  75. At what point and for how long is a TB patient administered isoniazid, rifampin and pyrazinamide?
    The first 2 months of treatment
  76. After the first two months these drugs are used to treat TB for 4 months:
    isonazid and rifampin
  77. The two drugs that are used to treat TB for the first 6 months are:
    isonazid and rifampin
  78. isonazid and rifampin are used to treat Tb during which treatment stages?
    The first 6 months
  79. pyrazinamide is used to treat TB suring what treatment period?
    The first 2 months
  80. Quantiferon Gold TB test is positive when
    ESAT-6-nil or CFP-10-nil are greater than or equal to 0.35 IU/mL and 50% nil
  81. The majority of TB cases need treatment (true/flase)?
  82. The majority of TB cases are self limiting (true/false)
  83. Developing coutries are seeing an increase or decrease in TB infections?
  84. Most TB hosts know that they have been infected (True/Flase)
  85. Most common Mycobacterium (other than M. tuberculosis) to cause infection:
    Mycobacterium avium-intracellulare
  86. Treatment issues with non-M. tuberculosis infections
    Many are antibiotic resistant and so hard to treat.
  87. Mycobacterium infection often seen in HIV patients:
    Mycobacterium avium-intracellulare
  88. Types of infections caused by non-M. tuberculosis mycobacterium:
    pulmonary or disseminated
  89. Tuberculosis in Europe
    HIV patients have developed resistant tuberculosis strains which have entered the population in Geneva
  90. Tuberculosis cases in the U.S. reached a peak of what number in 1992
  91. What year did Tuberculosis recently peak above 26,000 cases in the U.S.?
  92. Tuberculosis cases are currently declining or increasing in the U.S.?
  93. U.S. TB cases are at about what number per year?
  94. Mycobacterium Leprae is also known as:
    Hansen's Disease
  95. Leprosy is a highly contagious disease (True/Flase)?
  96. How many cases of Leprosy are there worldwide?
    15 million
  97. Aquisition of Leprosy requires:
    Frequent and Prolonged conact
  98. Hansen's Disease is caused by:
    Mycobacterium Leprae
  99. Mycobacterium Leprae causes what disease
    Lesprosy or Hansen's Disease
  100. Mycobacterium Leprae resovoirs are:
    • Mouse footpad
    • 9 banded armadillo
  101. Characteristics of Tuburculoid Leprosy
    Anaesthetic Macules with Hypopigmentation
  102. Two major forms of leprosy
    Lepromatus and Tuberculoid
  103. The severe form of leprosy is called:
    Lepromatous Leprosy
  104. Lepromatous Leprosy is characterized by:
    Disfigurement and loss of periphreal nerve function and lepromas
  105. Lepromas are:
    Granulomatous thickenings
  106. In leprosy the acid fast bacilli invade what parts of the body preferentially?
    Cooler parts
  107. Leprosmas can be defined discretely as:
    Diffuse skin infiltrations of bacterial nodules of varying size.
  108. What stain is used for mycobacteria?
    •Acid-fast (Ziehl-Neelsen)
  109. What is unique about the cell wall of mycobacteria?
    • thicker
    • Hydrophobic
    • Waxy
    • Mycolic Acid/Mycolates

    cell wall consists of the hydrophobic mycolate layer and a peptidoglycan layer held together by arabinogalactan (polysaccharide)
  110. What is cord factor?
    • A virulence factor:
    • Glycolipid
    • Inhibits migration of PMN’s
    • Small quantities lethal in lab animals
    • Aundant in virulent strains
    • Asence = non-virulent
  111. What are photochromogens? Example?
    • When light is needed to produce colony pigments.
    • e.g. Mycobacterium kansassi which turn yellow orange in light
  112. What is a primary lesion?
    Changes in DNA due to mutagens. Manifests as a process of the pathological process (pustules/nodules)
  113. What is a Secondary lesion?
    occurs due to the evolution of a disease or due to primary lesions (scales/scabs)
  114. What is PPD? 
    purified protein derivative
  115. What mycobacterium infects HIV patients at a high rate?
    Mycobacterium avium-intracellare
Card Set
MIC 541-Lecture 20
MIC 541-Lecture 20: Mycobacterium