(M) Lesson 8.2: Mycobacterium (Part 2) Flashcards
Mycobacteria are classified according to pigment production and time of growth
Runyoun’s classification
- Group 1
- Yellow pigmented under a constant light source
- Non-pigmented in the dark
- Some can develop pigment due to carotenoids
Photochromogens
Photochromogens
- Common name is yellow bacillus
- Has beta-carotene → yellow pigment
- Nitrate (+)
M. kansasii
Photochromogens
- Associated with skin infection from contact with poorly chlorinated or unchlorinated fresh or salt water including aquariums and swimming pools
M. marinum
Photochromogens
- First recovered from Macaca Rhesus monkey
- Niacin (+)
M. simiae
Photochromogens
- Rarely isolated in the US
- Niacin (-)
M. asiaticum
A serious form of infection involving the formation of nodules on the elbow, knees toes, and fingers
Swimming pool granuloma
- 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
Scotochromogens
Scotochromogens
- Causes vertical lymphadenitis in children
- Niacin (+)
- Nitrate (-)
M. scrofulaceum
Scotochromogens
- An agent in pulmonary and cutaneous diseases
M. szulgai
Scotochromogens
- Agent in pulmonary infection with pre-existing lung pathology
- Produces branching colonies with aerial hyphae on corn meal agar → bird’s nest
M. xenopi
Scotochromogens
- Most common scotochromogen
- Aka tap water bacillus in a variety of water sources
- Tween 80 (+)
- Heat-stable catalase(+)
M. gordonae
Scotochromogens
- Normal flora
M. flavescens
Scotochromogens
- Grows at 520C
M. thermoresistable
- Group 3
- Do not develop pigment (non-pigmented)
Nonphotochromogens
Nonphotochromogens
- Aka Battey bacillus → from its outbreak in Battey State Hospital in Rome
- Increased frequency in AIDS px
M. avium-intracellulare complex
Nonphotochromogens
- Causes Tb in birds and chicken
M. avium
Nonphotochromogens
- Aka inert bacillus
- Produces cutaneous lesions → buruli ulcers in the skin
M. ulcerans
Nonphotochromogens
- From hot, cold water taps at 420C
M. xenopi
Yes, andito din siya </3
Nonphotochromogens
- Rare cause of arthritis and osteomyelitis
- Complex: because they have similar morphology and biochemical characteristics
M. terrae-triviale complex
Nonphotochromogens
- Agent of subcutaneous lesions, ulcers in immunosuppressed px
- Requires hemin
M. haemophilum
Nonphotochromogens
- Aka radish bacillus or radish water
M. terrae
Nonphotochromogens
- 2nd most common cause of pulmonary NTM disease in some areas of Northern EU
- 1st isolated from a px in Malmo, Sweden
M. malmoense
Nonphotochromogens
- Aka J. bacillus
- Non-pathogenic
- Isolated from gastric lavage
M. gastric
- Group 4
- Grows in 3-5 days in a culture media
- Are saprophytes
Rapid Growers
Rapid Growers
- Grows on MAC w/o crystal violet
- Commonly found in water, soil, dust
M. fortuitum
Rapid Growers
- Grows on MAC w/o crystal violet
- Commonly found in water, soil, dust
M. chelonae
Rapid Growers
T or F: M. phlei is in Group 4 (Rapid Growers)
T
Rapid Growers
- Confused with MTb in urine
M. smegmatis
- 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
Mycobacterium leprae
T or F: M. leprae has not been cultivated yet in vitro.
T
M. leprae is cultured in?
Armadillo or mouse food pads
Specimen used for M. leprae?
Earlobe or nasal scrapings
Stain used for M. leprae?
Fite Faraco Stain
- Demonstrated in the tissue sections
- More sensitive than Ziehl-Neelsen in M. leprae detection in tissues
Fite Faraco Stain
- 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
Leprosy
What antibiotics are used for leprosy?
Dapsone with rifampicin, and clofazimine (multi-drug therapy)
