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Atypical Mycobacterium

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Atypical Mycobacterium Powered By Docstoc
					Ali Somily MD
 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
 Other names
  Mycobacteria other than tuberculosis (MOTT)
  Atypical
  Environmental
  Opportunistic
 Variable   pathogenicity and geographic
  regions
 40% cause diseases in human
 Immunosuppressed host
 Water, soil, food and animals
 Does not spread from person to another
 Relatively resistant to chlorination and
  ozonization
 Outbreak and Pseudo-outbreak in the
  hospital
 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            Slow Growers
 Days in broth and < 1    1-2 weeks in broth
  week in solid media       and 2-4 weeks in
 M.abscessus               solid media
 M.chelonae               M.avium

 M.fortutum               M.kansasii
                           M.scrofulaceum
                           M.ulcerans
                           M.xenopi
                           M.gordonae
 M.leprae   cannot be cultured
 M.marinum lower temperature required
 M.haemophilum lower temperature
  required and iron need to be added
 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
 Risk   factors
    Immunosuppression ( HIV, Medications )
    Aging
    BCG vaccination
    Cystic fibrosis
    Fibronodular bronchiectasis
    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
 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
 Pulmonary   disease
 Common etiological agents
 M. avium complex(MAC)
 M. kansasii
 M. abscessus
 M. xenopi
 Elderlymen with COPD
 Middle aged to elderly Non- smoking women
 CF patients
 Hypersensitivity pneumonitis
 M.Kansasii        M..xenopi
 Similarto TB      UK, Northern
 US midwest and     Europe and
  south              Canada, less
 AFB positive
                     common in US
                    Rural /farm area
 Probe positive
                    Very good outcome
 HIV CD4 <200
  pulmonary and
  disseminated
 Pulmonary   disease
 Treatment
 Treatment  with combined antimicrobials
 Resection if localized
 Lymph   node disease
 Definition
 Usually < 5 years of age
 Unilateral, submandibular site most
  common
 Onset of symptoms subacute
 Skin induration and sinus tract formation
  may occur
 R/O TB
 MAC (80%) is the most common followed
  by M. scrofulaceum
 Dx Fine needle or excisional Bx
 Lymph   node          Uncommon
  disease                etiological agents
 Common                M. scrofulaceum
  etiological agents    M.fortuitum/
 MAC                    peregrinum
 M. kansasii           M.abscessus/
 M. malmoense           chelonae
 M. haemophilum
 Lymph   node disease
 Treatment
 Surgical resection is usually curative
 Skin/soft tissue/bone/joint and tendons
 Definition
 History of trauma or superficial laceration
 Presence of a foreign body
 Skin/soft              Uncommon
  tissue/bone/joint       etiological agents
  and tendons
                         MAC
 Common etiological
  agents                 M. kansasii
 M. marinum             M. terrae
 M.                     M. haemophilum
  fortuitum/peregrinu
  m
 M.
  abscessus/chelonae
 M. ulcerans
 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
          tissue/bone/joint and tendons
 Skin/soft
 Treatment
 Debridement plus combined drug therapy
 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

 Anymycobacterium 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 truma ,
  post-op,cardiac ,mammoplasty and cosmotic
 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 should be carefully evaluated
  to determine the significance of an NTM
  isolate. The presence of the organism in a
  sterile site or 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, because of 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
 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

				
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