(M) Lesson 8.2: Mycobacterium (Part 2)

Question 1

Mycobacteria are classified according to pigment production and time of growth

Answer 1

Runyoun’s classification

Question 2

• Group 1
• Yellow pigmented under a constant light source
• Non-pigmented in the dark
• Some can develop pigment due to carotenoids

Answer 2

Photochromogens

Question 3

Photochromogens

• Common name is yellow bacillus
• Has beta-carotene → yellow pigment
• Nitrate (+)

Answer 3

M. kansasii

Question 4

Photochromogens

• Associated with skin infection from contact with poorly chlorinated or unchlorinated fresh or salt water including aquariums and swimming pools

Answer 4

M. marinum

Question 5

Photochromogens

• First recovered from Macaca Rhesus monkey
• Niacin (+)

Answer 5

M. simiae

Question 6

Photochromogens

• Rarely isolated in the US
• Niacin (-)

Answer 6

M. asiaticum

Question 7

A serious form of infection involving the formation of nodules on the elbow, knees toes, and fingers

Answer 7

Swimming pool granuloma

Question 8

• Group 2
• Pigmented under the presence and absence of light
• Yellow to orange in the dark
• Intensified to orange to red under a constant light source for about 2 weeks

Answer 8

Scotochromogens

Question 9

Scotochromogens

• Causes vertical lymphadenitis in children
• Niacin (+)
• Nitrate (-)

Answer 9

M. scrofulaceum

Question 10

Scotochromogens

• An agent in pulmonary and cutaneous diseases

Answer 10

M. szulgai

Question 11

Scotochromogens

• Agent in pulmonary infection with pre-existing lung pathology
• Produces branching colonies with aerial hyphae on corn meal agar → bird’s nest

Answer 11

M. xenopi

Question 12

Scotochromogens

• Most common scotochromogen
• Aka tap water bacillus in a variety of water sources
• Tween 80 (+)
• Heat-stable catalase(+)

Answer 12

M. gordonae

Question 13

Scotochromogens

• Normal flora

Answer 13

M. flavescens

Question 14

Scotochromogens

• Grows at 520C

Answer 14

M. thermoresistable

Question 15

• Group 3
• Do not develop pigment (non-pigmented)

Answer 15

Nonphotochromogens

Question 16

Nonphotochromogens

• Aka Battey bacillus → from its outbreak in Battey State Hospital in Rome
• Increased frequency in AIDS px

Answer 16

M. avium-intracellulare complex

Question 17

Nonphotochromogens

• Causes Tb in birds and chicken

Answer 17

M. avium

Question 18

Nonphotochromogens

• Aka inert bacillus
• Produces cutaneous lesions → buruli ulcers in the skin

Answer 18

M. ulcerans

Question 19

Nonphotochromogens

• From hot, cold water taps at 420C

Answer 19

M. xenopi

Yes, andito din siya </3

Question 20

Nonphotochromogens

• Rare cause of arthritis and osteomyelitis
• Complex: because they have similar morphology and biochemical characteristics

Answer 20

M. terrae-triviale complex

Question 21

Nonphotochromogens

• Agent of subcutaneous lesions, ulcers in immunosuppressed px
• Requires hemin

Answer 21

M. haemophilum

Question 22

Nonphotochromogens

• Aka radish bacillus or radish water

Answer 22

M. terrae

Question 23

Nonphotochromogens

• 2nd most common cause of pulmonary NTM disease in some areas of Northern EU
• 1st isolated from a px in Malmo, Sweden

Answer 23

M. malmoense

Question 24

Nonphotochromogens

• Aka J. bacillus
• Non-pathogenic
• Isolated from gastric lavage

Answer 24

M. gastric

Question 25

* Group 4 * Grows in 3-5 days in a culture media * Are saprophytes

Answer 25

Rapid Growers

Question 26

# Rapid Growers * Grows on MAC w/o crystal violet * Commonly found in water, soil, dust

Answer 26

M. fortuitum

Question 27

# Rapid Growers * Grows on MAC w/o crystal violet * Commonly found in water, soil, dust

Answer 27

M. chelonae

Question 28

# Rapid Growers T or F: M. phlei is in Group 4 (Rapid Growers)

Answer 28

T

Question 29

# Rapid Growers * Confused with MTb in urine

Answer 29

M. smegmatis

Question 30

* Belongs to the non-cultivable, NTM * An agent of leprosy or Hansen’s disease * Acid-fast bacilli * **Morphology: **cigarette packet/picket fence → parallel in one another

Answer 30

Mycobacterium leprae

Question 31

T or F: M. leprae has not been cultivated yet in vitro.

Answer 31

T

Question 32

M. leprae is cultured in?

Answer 32

Armadillo or mouse food pads

Question 33

Specimen used for M. leprae?

Answer 33

Earlobe or nasal scrapings

Question 34

Stain used for M. leprae?

Answer 34

Fite Faraco Stain

Question 35

* Demonstrated in the tissue sections * More sensitive than Ziehl-Neelsen in M. leprae detection in tissues

Answer 35

Fite Faraco Stain

Question 36

* Also called **Hansen’s Disease** * By M. leprae * Affects the nerves, skin, eyes, and lining of the nose * Transmission is **via droplets** * Incubated for **9 months to 20 years** * Treated using a combination of antibiotics

Answer 36

Leprosy

Question 37

What antibiotics are used for leprosy?

Answer 37

Dapsone with rifampicin, and clofazimine *(multi-drug therapy)*