[Micro] atypical mycobacterium

 All mycobacterial species except those
that cause tuberculosis (TB)
 Mycobacterium tuberculosis complex
includes M. tuberculosis
 including M. tuberculosis subsp canetti
 M.bovis
 M. bovis BCG strain
 M. africanum
 M. caprae
 M. microti
 M. pinnipedii
 Leprosy (M. leprae).

 1954 Runyon first NTM classification
 >100 NTM species(150)
 Other names
 Mycobacteria other than tuberculosis (MOTT)
 Atypical
 Environmental
 Opportunistic
 Variable pathogenicity and geographic
regions
 40% cause diseases in human
 Immunosupp host; more virulent lesions

 Water(fresh/salt) soil, food and animals:
 NOT person to person
 cigarette; paper, tobacco, filter
 Does not spread from person to another
 Relatively resistant to chlorination and
ozonization
 Outbreak and Pseudo-outbreak in the hospita
 HIV and dialysis patients
 Improve laboratory methods  reporting
 MAC 40%,rapidly growing 10%,15%
unknown,25% M.gordonae,2.5%
M.kansasii(MW USA and UK) and 1% M.xenopi
(Ontario)

 Rapid Growers
 Days in broth
 < 1 week in solid
media
 M.abscessus
 M.chelonae
 M.fortutum
 M smegmatis
 Slow Growers
 1-2 weeks in broth
2-4 weeks in solid
media
 M.avium
 M.kansasii
 M.scrofulaceum
 M.ulcerans
 M.xenopi
 M.gordonae

 M.leprae cannot be cultured
 M.marinum lower temperature required
 M.haemophilum lower temperature & Fe
 M.ulcerans lower temperature required
 M.genavense very slow growth in broth
 DNA probes for MAC, M. kansasii and M.
gordonae available
 Identification and sensitivity needed

 Highly Virulent Low virulence
 Person-person Environment
contact
PPD + PPD-
S to ATT not typical ATT

 Risk factors
 Immunosuppression ( HIV, Medications )
 Aging esp western population esp MAC
 BCG vaccination rates
 Cystic fibrosis
 Fibronodular bronchiectasis
 Decrease incidence of TB in North America:
relative more incidence of NTM

 Common clinical syndromes:
1. Lymphadenopathy
2. Chronic pulmonary disease
3. Skin and soft tissue infections (often
associated with trauma or a foreign body)
sometimes with extension to bone and joint
4. Disseminated disease.

 Pulmonary disease: 70-75% isolates of
NTM
 Definition
 Usually adults
 Symptoms of cough, sputum production,
weight loss
 Two or more sputum isolates or one isolate
from, BAL, Bx, sterile site
 Distribution of isolates varies regionally
 MAC, rapid growers, M kansassi & M xenopi

 Pulmonary disease
 Common etiological agents
 M. avium complex(MAC)
 M. kansasii: one + sample diagnostic
 M. abscessus
 M. xenopi

 Elderly men with COPD
 Middle aged to elderly Non- smoking women
 CF patients
 Hypersensitivity pneumonitis

 M.Kansasii
 Similar to TB
 US midwest and
south
 AFB positive
 Probe positive
 HIV CD4 <200
pulmonary and
disseminated
 M..xenopi
 UK, Northern
Europe and
Canada, less
common in US
 Rural /farm area
 Very good outcome

 Pulmonary disease
 Treatment
 Treatment with combined antimicrobials
 Resection if localized

 Lymph node disease
 Definition
 Usually <5 years age; well; no h/o contact
 Unilateral submandibular site commonest
 Sub-mental, preauricular
 Onset of symptoms subacute
 Skin induration inflamation,suppuration &
sinus tract formation
 R/O TB
 MAC (80%) is the most common followed
by M. scrofulaceum
 Dx Fine needle or excisional Bx

 Lymph node
disease
 Common
etiological agents
 MAC
 M. kansasii
 M. malmoense
 M. haemophilum
 Uncommon
etiological agents
 M. scrofulaceum
 M.fortuitum/
peregrinum
 M.abscessus/
chelonae

 Lymph node disease
 Treatment
 Surgical resection is usually curative

 Skin/soft tissue/bone/joint and tendons
 Definition
 History of trauma: injection, pedicure,
aucupuncture, surgery, cosmetic surgery
involving implants
 or superficial laceration
 Presence of a foreign body
 May grow in ‘sterilized water’, presence of
chlorine, glutaraldehyde, formaldehyde.
Cause post op infection

 Skin/soft
tissue/bone/joint
and tendons
 Common etiological
agents
 M. marinum
 M.
fortuitum/peregrinu
m
 M.
abscessus/chelonae
 M. ulcerans
 Uncommon
etiological agents
 MAC
 M. kansasii
 M. terrae
 M. haemophilum

 Water ,fish
 Lake, bay,ocean,pool,aquarium
 1-2 month IP  granulomatous nodular –
ulcerative lesions (hands)
 Bx for diagnosis

Fish tank granuloma/ M.marinum

Buruli ulcer /M.ulcerans
 Chronic cutanous
ulcer
 Africa mostly
 Debridment

 Skin/soft tissue/bone/joint and tendons
 Treatment
 Debridement plus combined drug therapy

 C/E Blood ; TLC, DLC
 AB: anti-neutrophil cytoplasmic/ perinuclear
anti neutrophil cytoplasmic AB
 ESR
 Angiotensin converting enzyme
 X-RAY: chest, CAT thorax
 Culture: sputum, BAL
 PPD
 Pulmonary function tests
 Lung biopsy

 Disseminated
 Definition
 HIV or other immunosuppressive disease
 Symptoms: fever, weight loss, diarrhea
 Any site possible
 No trauma necessary

 Disseminated
 Prevention & treatment
 Prevention of MAC in HIV by prophylaxis
 Treat positive blood culture aggressively

 Disseminated
 Common etiological agents
 MAC
 M. genavense
 M. abscessus/chelonae
 M. haemophilum
 Any mycobacterium may cause disease in
association with significant
immunosuppression HIV CD4 < 50), and
any localized lesion may disseminate.

 M.fortutum
 M.abscessus
 M.chelonae
 Skin and soft tissue infection after trauma ,
post-op, cardiac, mammoplasty and cosmetic
 Pulmonary M.abscessus > M.fortutum
 Indolent, progressive
 Cavitary uncommon
 Mild systemic symptoms

 Worldwide –esp in tropical countries
 Transmission rout unknown
 Can not be cultured
 Syndromes
 Lepromatous
 Tuberculoid
 Mixed
 Treatment 6-months to 2 years
 Dapsone + Rif +/- clofazimine

 Principles of Treatment of NTM Disease
 1. Patients evaluated to determine the
significance of an NTM isolate.
 Presence in sterile site
 repeatedly from airway secretions in
association with a compatible clinical and
radiologic picture confirms the diagnosis.
 2. Treatment of rapidly growing
mycobacteria should be guided by in vitro
susceptibilities.
 Other drug susceptibility testing is not
standardized.

 3. Treatment should usually combine at least
two drugs of proven efficacy.
 4. Contact follow-up is not necessary since
NTM are not transmitted from person to
person.
 5. Duration of therapy has not been
determined; in general, 6-12 months is
required following negative cultures.

 6. In soft tissue infections:
 rapidly growing mycobacteria, a
combination of debridement and treatment
with antimicrobials is recommended.
 For selection of antimicrobial agents,
consultation with the laboratory should be
undertaken regarding the reliability of in
vitro testing.

 MAC Clarithromycin or azithromycin +
ethambutol+Rifampin (CARE)
 M. xenopi Rifampin+Ethambiotol +INH
 M. kansasii Rifampin + Ethambutol
 M. malmoense Rifampin or Ethambutol
 M. marinum Rifampin or Clari +
Ethambutol 2-3 months
 Rapid growers doxycycline, amikacin,
imipenem, quinolones, sulfonamides,
cefoxitin, clarithromycin

 M. haemophilum Clarithromycin,
Rifampin Cipro or Amikacin
 M. genavense Clarithromycin,
Rifabutin or AmikacinEthambutol
 M. ulcerans Clarithromycin,
Rifampin, Ethambutol or PAS (
Paraaminosalicylic acid)
 MAC prophylaxis Azithromycin ,
Clarithromycin or Rifabutin 300 if CD4
<50x 106/L

[Micro] atypical mycobacterium

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[Micro] atypical mycobacterium