-
what is the genus under the family mycobacteriaceae?
Mycobacterium (AFB)
-
how many recognized species of Mycobacterium exist?
up to 100
-
These are aerobic non spore forming, non encapsulated, slight curved or straigt rods that are sometimes branching, filaments or mycelium-like growth.
Mycobacterium
-
Mycobacterium are _____-fast and _____-fast, non motile, not readily stained gram positive rods.
-
Mycobacterium have a high _____ content of cells and cell walls.
lipid
-
Raidly-growing Mycobacterium require how many days on simple media?
2-3 days
-
disease-associated species of Mycobacterium require how many weeks on complex media?
2-6
-
how are Mycobacterium incubated?
35oC in 5-10% CO2 in the dark
-
This is when cell wall resists decolorization by acidified alcohol.
Acid fastness
-
This describes two or more species, distinction between spp. has no medical importance.
complex
-
What are the three species in the M. tuberculosis complex?
- M. tuberculosis
- M bovis/M. bovis (BCG)
- M. africanum
-
This classification system is used for ID of Mycobacterium for public health purposes.
Runyon Classification system
-
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
-
What are the two organisms in Group I of the Runyon Classification System?
-
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
-
What are the two organisms in Group II of the Runyon classification system?
- M. gordonae
- M. scrofulceum
-
This group of the Runyon Classification System has no pigment in light or dark > 7 days on solid media.
Group III: Nonphotochromogens
-
What are the two organism in group III of the Runyon classification system?
- M. avium complex
- M. ulcerans
-
What group of the Runyon Classification System takes <7 days to grow on solid media?
Group IV: Rapid growers
-
What are the three organisms in group IV of the Runyon Classification System?
- M. fortuitum
- M. chelonae
- M. smegmatis
-
What is the Non-cultivatable NTM in the Runyon Classification System?
M. leprae
-
What is the solid Agar based media used for Mycobacterium?
Middlebrook 7H10 and 7H11
-
What is the Egg based solid media used for Mycobacterium?
Lowenstein Jensen (LJ)
-
What are the four liquid media used for Mycobacterium?
- Middlebrook 7H9
- Bactec 12B
- Septi-check AFB
- Mycobacteria growth indicator tube
-
What are the three rapid methods for diagnosis available for Mycobacterium?
- Acid-Fast smears
- Gas-Liquid and high performance liquid chromatography
- AFB flurochrome
-
What are the four Automated detection systems used for Mycobacterium?
- Bactec 460 TB system
- Bactec 9000 MB
- Bactec MGIT 960
- ESP culture system II
-
What is the automated system used for Mycobacterium that uses radiometric principle and C-labeled substrates.
Bactec 460 TB system
-
Conventional ID of Mycobacterium is based mainly on what three things?
- Growth rate
- Pigmentation (photochromogen)
- Niacin accumulation
-
This is the single best test to ID Mycobacterium tuberculosis?
Niacin Test: +
-
This Mycobacterium spp. is nitrate (+), urease (+), 68C Catalase (=), and resembles bread crumbs- rough, dry colonies, luxurious growth.
M. tuberculosis
-
This is a highly contagious disease spread by airbone droplets, inhalation of single viable organism leads to infection.
M. tuberculosis
-
M. tuberculosis has a high prevalence in patients with ______.
AIDS
-
What are three lung infections caused by M. tuberculosis?
- Granuloma
- Caseous necrosis
- Ultimately cavitary disease
-
What are three symptoms of Pulmonary Tuberculosis?
-
Specimen for ID of Pulmonary Tuberculosis inculdes ___ first AM sputum samples which should be delivered to the lab within ____ minutes.
-
What are the following results for M. bovis?
Niacin:
Nitrate reduction:
- niacin: =
- Nitrate reduction: =
-
this airborne organism is associated with bovine and human tuberculosis, and contracted via ingestion of contaminated mild, not prevaent due to pasteurization.
M. bovis
-
What are the following results for M. kansasii?
Niacin:
Nitrate reduction:
Urease:
68oC Catalase:
- Niacin: =
- Nitrate: +
- Urease: +
- 68oC Catalse: +
-
this organism was originally called "yellow bacillus"
M. kansasii
-
what is the natural reservoir for M. kansasii?
tap water
-
M. kansasii is assocated with what two diseases?
- Chronic pulmonary Dx
- Extra pulmonary Dx
-
M. kansasii will cause cervical lymphadenitits and cutaneous dx in what disease?
Extra pulmonary Dx
-
This organisms is isolated from fresh water and salt water, frequently causes cutaneous infections in fish hadlers and swimming pools.
M. marinum
-
this Mycobacterium is genitalia normal flora and usually a contaminant.
M. smegmatis
-
This mycobacterium is a tap water contaminant.
M. gordonae
-
This ubiquitous Mycobacterium is commonly isolated species in US HIV patients.
M. Avium complex (MAC)
-
What are the four organisms in the M. avium compex (MAC)?
- M. avium
- M. intracellulare
- M. paratuberculosis
- M. lepreamurium
-
This Mycobacterium can causes disseminated disease in AIDS patients, and pumonary infections, cervical lymphadenitis, and Disseminated disease in other patients.
M. avium complex (MAC)
-
This Mycobacterium organism is seen in raw milk, soil, water, and dairy.
M. scrofulceum
-
Pathogenic and epidemiologic studes of this Mycobacterium are difficult becuase it cannot be grown in vitro.
M. leprae
-
Diagnosis of this Mycobacterium are made through histopathological examination of skin lesion.
M. leprae
-
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)
-
M. leprae probably do not grow in ______ organs.
internal
-
What are the two forms of Leprosy?
- Lepromatous-form
- Tuberculoid and neural lesions
-
In what form of Leprosy are organisms rare?
Tuberculoid and neural lesions
-
In what form of Leprosy are bacilli abundant in tissue, and produce stuffed-cell granulomas.
Lepromatous-form
-
This is a drapid growing Mycobacterium associated with post operative infection, skin and soft tissue infection, and pulmonary infection.
M. fortuitum
-
This is a GP, partially acid fast aerobic actinomycetes that has a beaded appearance on gram stain, is aerobic, and catalase (+).
Nocardia asteroides
-
This organism is associated with mycetoma, lymphocutaneous infections and skin abcess cellulitis in immunocompetent patients.
N. asteroides
-
What is the greatest single problem in mycobacteria recovery?
presence of large numbers of contaminating microorganisms.
-
Mycobacterium specimens should be refrigerated if not processed within __ hour.
1
-
what is used as an expectorant for collection of sputum samples in patients with non-productive cough?
10% NaCl solution
-
Gastric lavage is collected from ______ and others unable to cooperate with sputum induction procedures.
infants
-
Gastric lavage collection bottle should contain what?
alkaline buffer
-
CSF should be centrifuged for 30 minutes at what speed?
3600
-
homogenization and decontamination is required for what four specimens?
- Sputum
- Gastric lavage
- Tissues (Following grinding)
- Other body fluids (except urine)
-
What type of BSC hood should be used for Mycobacterium?
Laminar flow hood
-
What are the two decontaminants for Mycobacterium?
- Sodium hydroxide (NaOH)
- Zephiran-trisodium phosphate
-
What is used as a digestant for Mycobacterium?
N-acetyl-L-cysteine (NALC)
-
What is the purpose of a digestant in Mycobacterium?
liquefies mucus
-
What is used as a neutralization solution for Mycobacterium?
phosphate buffer
-
What is the pH of the phosphate buffer nutralization solution for mycobacterium?
pH 6.8
-
how are Mycobacterium specimens incubated?
35oC at 5-10% CO2
-
if suspected what two Mycobacterium should be incubated at 25-30oC?
-
AFB cultures are kept for ___ weeks, examine daily.
8
-
This very infectious Mycobacterium can penetrate skin and can survive 5% phenol for 24 hours.
M. tuberculosis
-
What BSL is required for labs that process mycobacterium?
BSL 2
-
Cultivating what two Mycobacterium requires BSL 3?
-
Tuberculin-negative laboratory and hospital personnel are tested _______.
annually
-
All Mycobacterium procedures and work are performed in what class laminar flow hood with UV light.
-
Where are centrifuges and shaking machines kept when testing for Mycobacterium?
inside laminar flow hood
-
Germicidals and disinfectants used around Mycobacterium should aslo be what?
Tuberculocidal
-
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
-
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
-
What are the three types of acid fast stain?
- Ziehl-Neelsen (hot stain)
- Kinyoun (cold stain)
- Fluorochrome stain (UV microscope)
-
This stain contains 3g basic fuchsin, 10 ml 90-95% ethanol, and 90 ml 5% aqueous phenol (carbolic acid).
Carbolfuchsin stain (mixture)
-
What are the two reagents used in stains for mycobacterium?
- Acid-alcohol
- methylene blue counterstain
-
this reagent used in Mycobacterium stain contains 3 ml concentrated HCL added slowly to 97ml of ethanol in this order, solution may get hot.
Acid-alcohol
-
What three reagents are in the Fluorochrome stain?
- Auramine-rhodamine reagent
- Acid-alcohol
- Potassium permanganate
-
Fluorochrome stain is viewed using what type of microscope?
UV microscope
-
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
-
this heat fixed stain should NOT be heated until steaming.
Kinyoun
-
what color are mycobacteria stained in acid-fast staining?
red on light blue background
-
how many control slides should be made per suspect slide in acid-fast staining?
one
-
how should the positve control smear appear for acid-fast staining?
- red, small, slightly curved bacilli
- possibly beaded and tapered ends
- blue background
-
negative acid-fast staining smear should display numerous ______ (non-acid-fast) bacilli.
blue
-
What is the organism and strain that is used for acid-fast staining quality control?
M. tuberculosis strain H37rv
-
A minimum of how many fields should be scanned before reporting a negative sample in acid-fast staining?
300
-
What is the non-tuberculosis species that appears pleomorphic, usually coccoid in the acid fast stain?
M. avium complex
-
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
-
how are Acid-fast bacilli reported in Acid-fast staining?
- Positive for acid-fast bacilli
- negative
-
other pathogenic of non-pathogenic mycobacteria or partially acid-fast organisms usually appear as what on the acid-fast stain?
atypical rods
-
if only one or two acid fast bacilli are seen what should be done?
recommend confirmation with new specimen prior to reporting
-
if 1-2 organisms are seen in 300 fields using acid-fast staining, what should be reported.
questionable
-
if 1-9 organisms are seen in 100 fields, in acid-fast staining, what should be reported?
1+
-
if 1-9 organisms are seen in 10 fields, using acid fast staining, what should be reported?
2+
-
if 1-9 organisms are seen per field using acid fast staining, what should be reported?
3+
-
if >9 organisms are seen per field in acid fast staining, what should be reported?
4+
|
|