Mycobacterium

Question 1

• Aerobes/anaerobes
• Slow growers EXCEPT
• Motility
• Granules

Answer 1

1. Strictly aerobes
2. M. fortuitum, M. chelonei
3. Non-motile
4. Much granules

Question 1

3 GROUPS OF MYCOBACTERIUM

1. causes Tb
2. Other name: NTM (non-tuberculosis mycobacterium)
3. Hansens disease

Answer 1

1. M. tuberculosis complex: M. tuberculosis, M. bovis, M. africanum
2. M.O.T.T. (Mycobacteria other than tuberculosis)
3. M. leprae

Question 2

● Robert Koch in 1882
● Obligate aerobe [Require CO2 for growth (5-10%)]
● AKA Koch bacillus
● Cord factor & sulfatides (sticky response)
● A mature colony takes eight (8) weeks to grow.

Answer 2

MYCOBACTERIUM TUBERCULOSIS

Question 3

MYCOBACTERIUM TUBERCULOSIS

Specimen:
1. 3 consecutive days
2. If some infants and elderly persons can’t provide sputum
3. Pellicle of web like clot
4. Increased ADA
(Adenosine Deaminase)

Answer 3

1. Sputum
2. Bronchoscopy secretions
3. CSF
4. Serous fluid

Question 4

● Contains mucin and organic debris
● The pre-treatment stage is necessary to ensure that the organic debris and mucin will dissolve or decontaminate the specimen used for the Mycobacterium tuberculosis isolation.

Answer 4

Sputum

Question 5

Mycobacterium tuberculosis

1. Remove normal flora & other contaminating organism
2. Break disulfide bond in mucus trap MTb
3. Digestant and decontaminating agent
4. Liquefying agent
5. Most common method
6. digestant-decontamination; Shortens exposure time
7. Decontaminate specimens contaminated
8. Liquefies sputum; Requires longer time of exposure

Answer 5

1. Decontamination
2. Digestion
3. 2-4% NaOH
4. N-acetyl-L-cysteine (NALC)
5. Combination of NALC and NaOH
6. Benzalkonium Chloride (Zephiran)
7. 5-6% Oxalic acid
8. Trisodium phosphate

Question 6

Mycobacterium tuberculosis: stains

1. Hematoxylin instead of methylene blue as counterstain
2. More sensitive than the carbolfuchsin stains; Bright, yellow-orange bacilli against a dark background
3. For color blind individuals (MTb: black)
4. Other 2

Answer 6

1. Fite-faraco’s
2. Auramine-rohdamine fluorochrome stain (Traunt’s)
3. Spengler’s
4. Pappenheim’s, Baumgarten’s

Question 7

National Standard Reporting Scale (RITM)

1. No AFB seen in ??? visual fields
2. 1-9 AFB/ 100 visual fields
3. number of Afb/ ??? visual fields
4. ??? AFB/ OIF in at least ??? visual fields
5. ??? AFB/ OIF in at least ??? visual fields

Answer 7

1. 300 - 0
2. +n
3. 10-99, 100 - 1+
4. 1-10, 50 - 2+
5. > 10, 20 - 3+

Question 8

familiariza k analang

Answer 8

xCulture: Requires increased protein

a. Agar based
Duboi’sOleic Acid Albumin Medium Mitchison’sMedium Middlebrook7H10-7H11: Anti-susceptibility test

b. Egg-based
Inhibitor = malachite green
Petragnanimedium: used or heavily contaminated specimen (increased conc. of MG)
Lowenstein-Jensen medium American Thoracic Society Dorset Egg medium

c. Liquid media
Bactec12B
Septi-Check
Middlebrook7H9

Question 9

Mycobacterium tuberculosis: stains

Colonies:
Resembles:

Answer 9

○ Tan to buff colonies
○ Dry, rough, warty & granular
○ Resembles: cauliflower

Question 10

ANTI-TUBERCULOSIS AGENTS

● Rifampicin,
● Isoniazid
● Pyrazinamide
● Ethambutol
● Streptomycin

Answer 10

Primary drugs

Question 11

ANTI-TUBERCULOSIS AGENTS

● Ethionamide
● Capreomycin
● Ciprofloxacin
● Ofloxacin
● Kanamycin
● Cyclosrine
● Rifambutin

Answer 11

Secondary drugs

Question 12

Biochemical tests

Principle:
● Niacin + Niacin Ribonucleotide +
Aniline Dye + Cyanogen Bromide
(+) yellow MTb
(-) no color change M. bovis

Answer 12

Niacin test

Question 13

Medium:
● Tween 80 & Reagent: 30% H2O2
Principle:
● Tween 80 + Mycobacteria + 30%
H2O2+ heat at 68°C (20 mins)

Answer 13

Catalase Test at 68°C (Heat stable)

Question 14

Catalase Test at 68°C (Heat stable)

(-) no bubbles

ano organism

Answer 14

M. kansasii MTb

Question 15

HCL + Sulfanilamide +
n-napthtylethylene diamine

Answer 15

Nitrate Reduction Test

Question 16

Nitrate Reduction Test

(+) Pink/red color
(-) no color change

Answer 16

positive:
M. kansasii
M. szulgai
M. fortuitum
M. tuberculosis

negative:
M. intracellulare

Question 17

Tween 80 KOH

(+) red
(-) no red/ amber

Answer 17

M. kansasii (+)
M. avium (-)

Question 18

Tellurite Reduction Test

(+) smooth fine black precipitate
(-) gray clumps

Answer 18

M. avium (+)
M. M. kansasii (-)

kabaligtaran ng tween 80 KOH

Question 19

For rapid growers
Principle:
● Tripotassium phenolphthalein
disulfide/ sulfate acted upon by arylsulfatase to produce free phenolphthalein

Answer 19

Aryl Sulfatase Test

Question 20

Aryl Sulfatase Test

positive

Answer 20

(+) Pink/red color
M. fortuitum-chelonei

Question 21

TCH Thiophene-2- Carboxylic Acid Hydrazide) Susceptibility Test

Susceptible
Resistant

Answer 21

1. M bovis
2. MTb

Question 22

Principle:
● convert ferric ammonium citrate to
an iron oxide
● M.chelonae is also a rapid grower
but it is negative in iron uptake test

Answer 22

Iron uptake

Question 23

Iron uptake

positive

Answer 23

(+) rusty brown colonies - rapid growers
(-) no color formation (M. chelonae)

Question 24

Principle: ● Pyrazinamidase hydrolyzes pyrazinamide= pyrazinoic acid & ammonia in 4 days

Answer 24

Pyrazinamid ase

Question 25

# Pyrazinamid ase positive negative

Answer 25

(+) red pigment - MTb, M. marinum (-) no color formation - M. bovis, M. kansasi

Question 26

# Urease positive negative

Answer 26

M. scrofulaceum (+) M. gordonae (-)

Question 27

Sodium Chloride Tolerance High salt concentration (5% NaCl) in egg-based media inhibits the growth of most mycobacteria. (+)

Answer 27

M. flavescens M. triviale Most rapidly-growing Mycobacterium spp.

Question 28

# MOTT: GROUP 1: PHOTOCHROMOGENS 1. Also known as yellow bacillus (consisting of beta carotene); (+) Nitrate 1. Causes swimming pool granuloma 1. (-) Niacin

Answer 28

1. M. kansasii 2. M. marinum 3. M. simiae and M. asiaticum

Question 29

# MOTT: GROUP 3: NON PHOTOCHROMOGENS 1. Commonly causes tuberculosis in AIDS patients; Also known as Battey bacillus 2. Causes tuberculosis in birds and chickens 3. Also known as Innert bacillus; Buruli ulcers in skin 4. Hot, cold water taps at 42 °C 5. Also known as Radish bacillus 6. Also known as J bacillus

Answer 29

1. M. avium-intracellulare complex 2. M. avium 3. M. ulcerans 4. M. xenopi 5. M. terrae 6. M. gastri

Question 30

# MOTT: GROUP 2: SCOTOCHROMOGENS 1. Cervical lymph adenitis (neck region); (+) Niacin; (-) Nitrate 2. Also known as tap water bacillus; (+) Tween 80

Answer 30

1. M. scrofulaceum (scrofula) 2. M. gordonae

Question 31

# GROUP 4: RAPID GROWERS 1. Grows on MAC w/out crystal violet 2. Provides CO2 3. Confused with M. tuberculosis in urine

Answer 31

1. M. fortuitum, M. chelonae 2. M. phlei 3. M. smegmatis

Question 32

● Agent of Hansen’s disease ● Acid fast bacilli (AFB) ● Described as cigarette-packet / picket-fence ● Hydrolize 3,4-hydroxyl-phenylalanine (DOPA) ● Tropism to peripheral nerves

Answer 32

MYCOBACTERIUM LEPRAE

Question 33

# MYCOBACTERIUM LEPRAE 1. Specimen 2. Culture 3. Stain 4. Treatment

Answer 33

1. Earlobe or nasal scraping 2. non-synthetic medium (in a live animal); Armadillo pads 3. Fite Faraco stain 4. Dapsone, Sulfone

Question 34

# SKIN TEST FOR M. LEPRAE (LEPROMIN TEST) 1. Reaction observed after 24-48 hours 2. Reaction observed after 3-4 weeks

Answer 34

1. Fernandez (EARLY Reaction) 2. Mitsuda (LATE Reaction)

Question 35

● A screening test for M. tuberculosis ● Involves intradermal injection ● Wheal or induration formation will be observed ○ This is measured after 48 hours:

Answer 35

SKIN TEST FOR M. TUBERCULOSIS (MANTOUX TEST)

Question 36

# SKIN TEST FOR M. TUBERCULOSIS (MANTOUX TEST) Positive

Answer 36

>10 mm wheal