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Atypical Mycobacterium. Ali Somily MD. Nontuberculous Mycobacteria. 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
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Atypical Mycobacterium Ali Somily MD
Nontuberculous Mycobacteria • 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).
Nontuberculous Mycobacteria • 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
Nontuberculous Mycobacteria • 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)
Laboratory Diagnosis • Rapid Growers • Days in broth and < 1 week in solid media • M.abscessus • M.chelonae • M.fortutum • Slow Growers • 1-2 weeks in broth and 2-4 weeks in solid media • M.avium • M.kansasii • M.scrofulaceum • M.ulcerans • M.xenopi • M.gordonae
Special Diagnostic Problems • 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
Nontuberculous Mycobacteria • Risk factors • Immunosuppression ( HIV, Medications ) • Aging • BCG vaccination • Cystic fibrosis • Fibronodular bronchiectasis
Nontuberculous Mycobacteria • Common clinical syndromes: • Lymphadenopathy • Chronic pulmonary disease • Skin and soft tissue infections (often associated with trauma or a foreign body) sometimes with extension to bone and joint • Disseminated disease.
Nontuberculous Mycobacteria • 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
Nontuberculous Mycobacteria • Pulmonary disease • Common etiological agents • M. avium complex(MAC) • M. kansasii • M. abscessus • M. xenopi
M.Avium complex (MAC) • 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
Nontuberculous Mycobacteria • Pulmonary disease • Treatment • Treatment with combined antimicrobials • Resection if localized
Nontuberculous Mycobacteria • 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
Nontuberculous Mycobacteria • Lymph node disease • Common etiological agents • MAC • M. kansasii • M. malmoense • M. haemophilum • Uncommon etiological agents • M. scrofulaceum • M.fortuitum/ peregrinum • M.abscessus/ chelonae
Nontuberculous Mycobacteria • Lymph node disease • Treatment • Surgical resection is usually curative
Nontuberculous Mycobacteria • Skin/soft tissue/bone/joint and tendons • Definition • History of trauma or superficial laceration • Presence of a foreign body
Nontuberculous Mycobacteria • Skin/soft tissue/bone/joint and tendons • Common etiological agents • M. marinum • M. fortuitum/peregrinum • M. abscessus/chelonae • M. ulcerans • Uncommon etiological agents • MAC • M. kansasii • M. terrae • M. haemophilum
M.marinum • Water ,fish • Lake, bay,ocean,pool,aquarium • 1-2 month IP granulomatous nodular – ulcerative lesions (hands) • Bx for diagnosis
Buruli ulcer /M.ulcerans • Chronic cutanous ulcer • Africa mostly • Debridment
Nontuberculous Mycobacteria • Skin/soft tissue/bone/joint and tendons • Treatment • Debridement plus combined drug therapy
Nontuberculous Mycobacteria • Disseminated • Definition • HIV or other immunosuppressive disease • Symptoms: fever, weight loss, diarrhea • Any site possible • No trauma necessary
Nontuberculous Mycobacteria • Disseminated • Prevention & treatment • Prevention of MAC in HIV by prophylaxis • Treat positive blood culture aggressively
Nontuberculous Mycobacteria • 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.
Rapid Growers • 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
Leprosy • 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
Nontuberculous Mycobacterial Disease • 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.
Nontuberculous Mycobacterial Disease • 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.
Nontuberculous Mycobacterial Disease • 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.
Antimycobacterium • MAC Clarithromycin or azithromycin + ethambutol+Rifampin • M. xenopiRifampin+Ethambiotol +INH • M. kansasiiRifampin + Ethambutol • M. malmoenseRifampin or Ethambutol • M. marinumRifampin or Clari + Ethambutol 2-3 months • Rapid growersdoxycycline, amikacin, imipenem, quinolones, sulfonamides, cefoxitin, clarithromycin
Antimycobacterium • M. haemophilumClarithromycin, Rifampin Cipro or Amikacin • M. genavense Clarithromycin, Rifabutin or AmikacinEthambutol • M. ulceransClarithromycin, Rifampin, Ethambutol or PAS ( Paraaminosalicylic acid) • MAC prophylaxisAzithromycin , Clarithromycin or Rifabutin 300 if CD4 <50x 106/L