Mycobacteriaceae 7.13

  1. what is the genus under the family mycobacteriaceae?
    Mycobacterium (AFB)
  2. how many recognized species of Mycobacterium exist?
    up to 100
  3. These are aerobic non spore forming, non encapsulated, slight curved or straigt rods that are sometimes branching, filaments or mycelium-like growth.
  4. Mycobacterium are _____-fast and _____-fast, non motile, not readily stained gram positive rods.
    • acid
    • alcohol
  5. Mycobacterium have a high _____ content of cells and cell walls.
  6. Raidly-growing Mycobacterium require how many days on simple media?
    2-3 days
  7. disease-associated species of Mycobacterium require how many weeks on complex media?
  8. how are Mycobacterium incubated?
    35oC in 5-10% CO2 in the dark
  9. This is when cell wall resists decolorization by acidified alcohol.
    Acid fastness
  10. This describes two or more species, distinction between spp. has no medical importance.
  11. What are the three species in the M. tuberculosis complex?
    • M. tuberculosis
    • M bovis/M. bovis (BCG)
    • M. africanum
  12. This classification system is used for ID of Mycobacterium for public health purposes.
    Runyon Classification system
  13. This group of the Runyon classification System is yellow when exposed to light after growing in the dark for >7 days on solid media.
    Group I: Photochromogens
  14. What are the two organisms in Group I of the Runyon Classification System?
    • M. kansasii
    • M. marinum
  15. This group of the Runyon Classification System is yellow when grown in the light OR dark for >7 days on solid media.
    Group II: Scotochromogens
  16. What are the two organisms in Group II of the Runyon classification system?
    • M. gordonae
    • M. scrofulceum
  17. This group of the Runyon Classification System has no pigment in light or dark > 7 days on solid media.
    Group III: Nonphotochromogens
  18. What are the two organism in group III of the Runyon classification system?
    • M. avium complex
    • M. ulcerans
  19. What group of the Runyon Classification System takes <7 days to grow on solid media?
    Group IV: Rapid growers
  20. What are the three organisms in group IV of the Runyon Classification System?
    • M. fortuitum
    • M. chelonae
    • M. smegmatis
  21. What is the Non-cultivatable NTM in the Runyon Classification System?
    M. leprae
  22. What is the solid Agar based media used for Mycobacterium?
    Middlebrook 7H10 and 7H11
  23. What is the Egg based solid media used for Mycobacterium?
    Lowenstein Jensen (LJ)
  24. What are the four liquid media used for Mycobacterium?
    • Middlebrook 7H9
    • Bactec 12B
    • Septi-check AFB
    • Mycobacteria growth indicator tube
  25. What are the three rapid methods for diagnosis available for Mycobacterium?
    • Acid-Fast smears
    • Gas-Liquid and high performance liquid chromatography
    • AFB flurochrome
  26. What are the four Automated detection systems used for Mycobacterium?
    • Bactec 460 TB system
    • Bactec 9000 MB
    • Bactec MGIT 960
    • ESP culture system II
  27. What is the automated system used for Mycobacterium that uses radiometric principle and C-labeled substrates.
    Bactec 460 TB system
  28. Conventional ID of Mycobacterium is based mainly on what three things?
    • Growth rate
    • Pigmentation (photochromogen)
    • Niacin accumulation
  29. This is the single best test to ID Mycobacterium tuberculosis?
    Niacin Test: +
  30. This Mycobacterium spp. is nitrate (+), urease (+), 68C Catalase (=), and resembles bread crumbs- rough, dry colonies, luxurious growth.
    M. tuberculosis
  31. This is a highly contagious disease spread by airbone droplets, inhalation of single viable organism leads to infection.
    M. tuberculosis
  32. M. tuberculosis has a high prevalence in patients with ______.
  33. What are three lung infections caused by M. tuberculosis?
    • Granuloma
    • Caseous necrosis
    • Ultimately cavitary disease
  34. What are three symptoms of Pulmonary Tuberculosis?
    • Fever
    • Chills
    • Myalgias
  35. Specimen for ID of Pulmonary Tuberculosis inculdes ___ first AM sputum samples which should be delivered to the lab within ____ minutes.
    • 3
    • 30
  36. What are the following results for M. bovis?
    Nitrate reduction:
    • niacin: =
    • Nitrate reduction: =
  37. this airborne organism is associated with bovine and human tuberculosis, and contracted via ingestion of contaminated mild, not prevaent due to pasteurization.
    M. bovis
  38. What are the following results for M. kansasii?
    Nitrate reduction:
    68oC Catalase:
    • Niacin: =
    • Nitrate: +
    • Urease: +
    • 68oC Catalse: +
  39. this organism was originally called "yellow bacillus"
    M. kansasii
  40. what is the natural reservoir for M. kansasii?
    tap water
  41. M. kansasii is assocated with what two diseases?
    • Chronic pulmonary Dx
    • Extra pulmonary Dx
  42. M. kansasii will cause cervical lymphadenitits and cutaneous dx in what disease?
    Extra pulmonary Dx
  43. This organisms is isolated from fresh water and salt water, frequently causes cutaneous infections in fish hadlers and swimming pools.
    M. marinum
  44. this Mycobacterium is genitalia normal flora and usually a contaminant.
    M. smegmatis
  45. This mycobacterium is a tap water contaminant.
    M. gordonae
  46. This ubiquitous Mycobacterium is commonly isolated species in US HIV patients.
    M. Avium complex (MAC)
  47. What are the four organisms in the M. avium compex (MAC)?
    • M. avium
    • M. intracellulare
    • M. paratuberculosis
    • M. lepreamurium
  48. This Mycobacterium can causes disseminated disease in AIDS patients, and pumonary infections, cervical lymphadenitis, and Disseminated disease in other patients.
    M. avium complex (MAC)
  49. This Mycobacterium organism is seen in raw milk, soil, water, and dairy.
    M. scrofulceum
  50. Pathogenic and epidemiologic studes of this Mycobacterium are difficult becuase it cannot be grown in vitro.
    M. leprae
  51. Diagnosis of this Mycobacterium are made through histopathological examination of skin lesion.
    M. leprae
  52. This is an obligate intracellular parasite in man, confined largely to skin (cold surfaces), especially convex and exposed surfaces, testes, peripheral nerves.
    leprosy (Hanen's Disease)
  53. M. leprae probably do not grow in ______ organs.
  54. What are the two forms of Leprosy?
    • Lepromatous-form
    • Tuberculoid and neural lesions
  55. In what form of Leprosy are organisms rare?
    Tuberculoid and neural lesions
  56. In what form of Leprosy are bacilli abundant in tissue, and produce stuffed-cell granulomas.
  57. This is a drapid growing Mycobacterium associated with post operative infection, skin and soft tissue infection, and pulmonary infection.
    M. fortuitum
  58. This is a GP, partially acid fast aerobic actinomycetes that has a beaded appearance on gram stain, is aerobic, and catalase (+).
    Nocardia asteroides
  59. This organism is associated with mycetoma, lymphocutaneous infections and skin abcess cellulitis in immunocompetent patients.
    N. asteroides
  60. What is the greatest single problem in mycobacteria recovery?
    presence of large numbers of contaminating microorganisms.
  61. Mycobacterium specimens should be refrigerated if not processed within __ hour.
  62. what is used as an expectorant for collection of sputum samples in patients with non-productive cough?
    10% NaCl solution
  63. Gastric lavage is collected from ______ and others unable to cooperate with sputum induction procedures.
  64. Gastric lavage collection bottle should contain what?
    alkaline buffer
  65. CSF should be centrifuged for 30 minutes at what speed?
  66. homogenization and decontamination is required for what four specimens?
    • Sputum
    • Gastric lavage
    • Tissues (Following grinding)
    • Other body fluids (except urine)
  67. What type of BSC hood should be used for Mycobacterium?
    Laminar flow hood
  68. What are the two decontaminants for Mycobacterium?
    • Sodium hydroxide (NaOH)
    • Zephiran-trisodium phosphate
  69. What is used as a digestant for Mycobacterium?
    N-acetyl-L-cysteine (NALC)
  70. What is the purpose of a digestant in Mycobacterium?
    liquefies mucus
  71. What is used as a neutralization solution for Mycobacterium?
    phosphate buffer
  72. What is the pH of the phosphate buffer nutralization solution for mycobacterium?
    pH 6.8
  73. how are Mycobacterium specimens incubated?
    35oC at 5-10% CO2
  74. if suspected what two Mycobacterium should be incubated at 25-30oC?
    • M. marinum
    • M. ulcerans
  75. AFB cultures are kept for ___ weeks, examine daily.
  76. This very infectious Mycobacterium can penetrate skin and can survive 5% phenol for 24 hours.
    M. tuberculosis
  77. What BSL is required for labs that process mycobacterium?
    BSL 2
  78. Cultivating what two Mycobacterium requires BSL 3?
    • M. tuberculosis
    • M. bovis
  79. Tuberculin-negative laboratory and hospital personnel are tested _______.
  80. All Mycobacterium procedures and work are performed in what class laminar flow hood with UV light.
    • Class 2A
    • Class 2B
  81. Where are centrifuges and shaking machines kept when testing for Mycobacterium?
    inside laminar flow hood
  82. Germicidals and disinfectants used around Mycobacterium should aslo be what?
  83. This is designed for rapid diagnosis of organism with high lipid content in cell wall capable of binding fuchsin dye that is not removed by acid alcohol.
    Acid-Fast staining procedure
  84. What are the three uses of acid-fast staining procedure.
    • confirm acid-fast nature
    • monitor patients on antimycobacterial drugs
    • determine appropriate dilution for suceptibility testing
  85. What are the three types of acid fast stain?
    • Ziehl-Neelsen (hot stain)
    • Kinyoun (cold stain)
    • Fluorochrome stain (UV microscope)
  86. This stain contains 3g basic fuchsin, 10 ml 90-95% ethanol, and 90 ml 5% aqueous phenol (carbolic acid).
    Carbolfuchsin stain (mixture)
  87. What are the two reagents used in stains for mycobacterium?
    • Acid-alcohol
    • methylene blue counterstain
  88. this reagent used in Mycobacterium stain contains 3 ml concentrated HCL added slowly to 97ml of ethanol in this order, solution may get hot.
  89. What three reagents are in the Fluorochrome stain?
    • Auramine-rhodamine reagent
    • Acid-alcohol
    • Potassium permanganate
  90. Fluorochrome stain is viewed using what type of microscope?
    UV microscope
  91. these two acid-fast staining techniques are theoretically the same, but the first is more sensitive in detecting lightly staining organisms.
    • ziehl-neelsen
    • Kinyoun techniques
  92. this heat fixed stain should NOT be heated until steaming.
  93. what color are mycobacteria stained in acid-fast staining?
    red on light blue background
  94. how many control slides should be made per suspect slide in acid-fast staining?
  95. how should the positve control smear appear for acid-fast staining?
    • red, small, slightly curved bacilli
    • possibly beaded and tapered ends
    • blue background
  96. negative acid-fast staining smear should display numerous ______ (non-acid-fast) bacilli.
  97. What is the organism and strain that is used for acid-fast staining quality control?
    M. tuberculosis strain H37rv
  98. A minimum of how many fields should be scanned before reporting a negative sample in acid-fast staining?
  99. What is the non-tuberculosis species that appears pleomorphic, usually coccoid in the acid fast stain?
    M. avium complex
  100. If large numbers of typical forms of acid-fast bacilli are seen in acid-fast staining it is reasonable to assume they are what organism?
    M. tuberculosis
  101. how are Acid-fast bacilli reported in Acid-fast staining?
    • Positive for acid-fast bacilli
    • negative
  102. other pathogenic of non-pathogenic mycobacteria or partially acid-fast organisms usually appear as what on the acid-fast stain?
    atypical rods
  103. if only one or two acid fast bacilli are seen what should be done?
    recommend confirmation with new specimen prior to reporting
  104. if 1-2 organisms are seen in 300 fields using acid-fast staining, what should be reported.
  105. if 1-9 organisms are seen in 100 fields, in acid-fast staining, what should be reported?
  106. if 1-9 organisms are seen in 10 fields, using acid fast staining, what should be reported?
  107. if 1-9 organisms are seen per field using acid fast staining, what should be reported?
  108. if >9 organisms are seen per field in acid fast staining, what should be reported?
Card Set
Mycobacteriaceae 7.13
Microbiology Unit 7.13 Mycobacteriaceae