Non-TB mycobacterium Flashcards
What is the Runyan classification?
Runyan classification based on production of pigmentation, whether the pigmentation occurred in darkness or light, and growth rates
Grown in dark develop a pigment?
Scotochromogens
Grown in light and produce a yellow pigment?
Photochromogens
Name some examples from group I to IV
Class I: Photochromogens (M kansasii, M
marinum, M simiae, M asiaticum)
* Class II: Scotochromogens (M scrofulaceum,
M gordonae, M szulgai, M xenopi)
* Class III: Nonchromogenic (M avium-
intracellulare, M terrae, M paratuberculosis)
* Class IV: Rapid Growers (M chelonae, M
abscessus, M fortuitum)
What are the most important non pigmented species fast growers?
M abscessus, M fortuitum
What are slow growing NTMs?
M. avium complex (MAC, MAI, M. avium-intracellulare)
M. kansasii
M. ulcerans
M. xenopi
M. terrae complex
M. simiae
M. haemophilum
M. szulgai
M. genavensae
M. scrofulaceum
M. malmoense
Intermediately slow growing NTM?
M. marinum, M. gordonae
What is often caught in a swimming pool?
M. marinum
What are the major clinical syndromes of NTMs?
Chronic pulmonary disease
lymphadenitis
Skin and soft tissue
What are the most common NTM causes of pulmonary disease?
Mycobacterium avium-intracellulare
M. kansasii,
M. abscessus
What are the common NTM causing lymphadenitis?
MAI
M. scrofulaceum
M. malmoense
What are the common causes of NTM causing skin disease?
M. marinum
M. chelonae
What causes skeletal disease?
MAC/MAI, M. marinum, M. kansasii, M. fortuitum, M.
abscessus, M. chelonae
What NTM causes disseminated infection and in who?
HIV
MAI, M. kansasii and M. haemophilum
HIV negative patients - M. abscessus, M. chelonae
What NTM cause line infections/healthcare associated infections?
M. fortuitum, M. abscessus, and M. chelonae
Which NTM do Middle age male smokers, often heavy alcohol users get?
MAI, M. kansasii
Upper lobe cavitary disease; resembles M. tuberculosis disease
Which NTM do Older nonsmoking females with no apparent underlying disease get?
MAC
RML, lingular bronchiectasis (Lady Windermere Syndrome)
Which NTM causes Achalasia, chronic vomiting, lipoid pneumonia?
M. fortuitum, M. abscessus, MAI
What is the most common NTM in South America?
M.Kansasii
What is the most common NTM in the world?
MAC
(includes M. avium-intracellulare)
Do you treat everyone with positive NTM on sputum?
No!
- Symptomatic
- Aggressive clinically and radiologically
What are the public health concerns of NTM?
Nil
Non contagious
Live in environment everywhere
Most prominent risk factor for MAC?
Immunosuppression with CD4 less than 50
What is the transmission?
Ingestion or inhalation
Differentials of Cavitating lesions on CXR?
TB
Non-TB mycobacterium
Fungal
Bacterial
Parasitic
What are rice bodies? What causes it?
Granulomatous infection of tendon sheath
TB
NTM - MAC most common
fungal infection
What are globi?
Overwhelming bone marrow infiltration with an NTM
How does M.Kansasii present?
Almost always pulmonary disease, interstitial infiltrates and lobar infiltrates
Can be disseminated disease (in HIV)
Very similar to TB!
What is the Rx of M.Kansasii?
Same as TB except without the PZA
How do you differentiate species of NTM?
Culture
What is this?
M scrofulaceum
Differentials
- TB (more likely)
- M. malmoense
In who do you find M.haemophilum?
Immunocompromised
Aquatic reservoirs.
3 most common mycobacterium
M.TB
M.Leprae
M.Ulcerans
How do you manage a Buruli ulcer?
Clarithromycin and rifampin Surgical excision
Which NTM do you get from fresh water esp if an injury?
M.marinum
All patients reported contact
with fish tanks at home or work prior to infection.
Which NTM do you get from fresh water esp if an injury?
M.marinum
All patients reported contact
with fish tanks at home or work prior to infection.
Injury in a fish tank, Diagnosis?
Key differential?
Infection began as papulonodular lesion on finger or hand in all 8
patients, and remained confined to the skin and lymphatics.
(resembles sporotrichosis).
45 year old transplant patient, develops bilateral ulcerative lesions on Lower limbs, works as a farmer. Diagnosis?
M. abscessus/chelonae
Commonly found in tap water
Causes skin and soft tissue disease
How do you treat M.Kansasii
Same as TB minus the PZA
How do you treat MAC?
Clarith/azith plus rifampicin plus ethambutol (plus amino glycoside in some cases)
