Medscape is available in 5 Language Editions – Choose your Edition here.


Mycobacterium Chelonae Workup

  • Author: Alfred Scott Lea, MD; Chief Editor: Michael Stuart Bronze, MD  more...
Updated: Oct 06, 2015

Laboratory Studies

According to American Thoracic Society (ATS) criteria, diagnosis of Mycobacterium chelonae lung disease requires the following 3 elements[25] :

  • Pulmonary symptoms with consistent radiographic features (see Imaging Studies)
  • Exclusion of other diagnoses (especially tuberculosis and other nontuberculous mycobacteria [NTM])
  • Appropriate microbiological findings (which are listed immediately below)

Primary testing methodology

Primary testing methodology is sputum smear for acid-fast bacilli (AFB) and culture for mycobacteria.

Microbiological findings to satisfy ATS diagnostic criteria include the following (at least one needed for accurate diagnosis):

  • Positive culture from 2 separate sputum samples
  • One positive culture from bronchial wash or lavage
  • A biopsy specimen with appropriate histopathologic features and a positive culture from an associated bronchial wash or biopsy culture

Induced sputum samples may be substituted for expectorated sputum samples, but data establishing the effectiveness of this technique are lacking.

A single positive isolate may represent a contaminant or a persistent or transient colonizer without pathogenicity.[35, 36]

Swab culture for acid-fast bacillus

Swab specimens are less optimal than cultures obtained via aspiration. Notifying microbiology laboratory personnel to communicate clinical suspicion and concerns results in the proper procedures regarding adequate specimen processing to increase the yield and significance of cultures.

Interpret microbiological results with caution because a single positive culture, especially of a superficial lesion or sputum, may represent a contaminant or colonization. In one study from Spain, 13 of 24 isolates of M chelonae were deemed of questionable clinical significance.[17]

Species identification of the NTM as well as susceptibility studies performed by a competent reference laboratory are important steps when evaluating all forms of NTM, since their clinical presentation and manifestations, as well as their response to therapy, can be quite different.

Additional testing

If M chelonae,Mycobacterium abscessus or any rapidly growing mycobacteria (RGM)infection is discovered, additional testing for underlying disease may be needed. Speciation points to the clinical sequelae that can be anticipated.

An HIV test may be warranted, especially if disseminated disease with any NTM is diagnosed without an obvious underlying condition.

Sweat chloride and/or genetic screening for cystic fibrosis may be warranted if lung infection is found not only in a relatively young patient, but also in older patients with evidence of bronchiectasis.

A purified protein derivative (PPD) of tuberculin test should be considered to assist in ruling out tuberculosis. Similarly, interferon-gamma release assays (IGRA) may help identify a true Mycobacterium tuberculosis infection.

Susceptibility testing

Susceptibility testing should be performed on all isolates to guide treatment. General susceptibility results reported in the ATS guidelines are as follows[25] :

  • Tobramycin - 100%
  • Clarithromycin - 100%
  • Linezolid - 50-90%
  • Imipenem - 60%
  • Amikacin - 50%
  • Doxycycline - 25%
  • Ciprofloxacin - 20%

In vitro susceptibility testing may not correlate with in vivo results and vice versa.


Imaging Studies

Chest radiography

Perform chest radiography if pulmonary symptoms are present. Typical findings are bilateral patchy nodular or cavitary opacities (15% are cavitary) with an upper lobe predominance.

Normal chest radiographic findings with a single positive culture suggest that the organism is a contaminant or a transient colonizer and is not clinically significant. However, in the presence of chronic persistent pulmonary symptoms or repeatedly positive culture results, additional testing may be necessary.

Chest CT scanning

If the patient has significant respiratory symptoms or repeatedly positive cultures for the M chelonae with a lack of cavitary disease on chest radiography, high-resolution CT scanning is likely indicated.

Typical CT scan findings include bronchiectasis, “tree-in-bud” appearance, or diffuse small nodules, which may not be apparent on routine chest radiography.

If the chest radiographic findings are abnormal, chest CT scanning may be performed to obtain better definition of the abnormalities present. Small cavities, nodules, and lymphadenopathy may be detected.

CT scanning of the abdomen and pelvis

CT scanning of the abdomen and pelvis may be indicated to detect intra-abdominal or retroperitoneal abscesses. It may also be used to evaluate localizing signs or symptoms of soft-tissue infection, especially in patients with a recent history of abdominal wall injections.

Bone imaging, MRI, and nuclear imaging

These studies may be helpful in detecting suspected osteomyelitis or joint disease, especially in patients with a history of penetrating trauma.

MRI can be helpful in evaluating the anatomy sinus tracts and fistulae and whether underlying abscess formation, foreign material, or marrow edema (osteomyelitis) is present.

Gallium scanning may be useful to screen for supradiaphragmatic lymphadenopathy (intrathoracic or axillary).


Other Tests

Erythrocyte sedimentation rate or C-reactive protein assessments may be useful to differentiate colonizer and pathogen, but these are nonspecific tests and the results must be carefully evaluated within the clinical context of the patient.



Pulmonary procedures

Bronchoscopy is frequently indicated. Tests to be sent include bronchial washes for AFB culture and transbronchial biopsy samples sent for culture and histopathology. Bronchoalveolar lavage (BAL) may also be useful. Fungal cultures are typically sent as well, given an uncertain differential diagnosis.

Open or Video-assisted thorascopic (VATS) lung biopsy may be considered if suspicion is high but diagnostic criteria have not been met. Specimens for fungal and AFB cultures should be sent along with histopathology.

A positive culture from a sterile surgical biopsy is considered diagnostic for M chelonae.

Lung biopsy histology documenting the presence of AFB or granulomas along with positive sputum or BAL culture is considered diagnostic.

Skin tests

Skin testing with nontuberculous mycobacterial specific antigens is nonspecific and generally not indicated. These tests are not commercially available.

A positive standard PPD test result may raise suspicion for an unsuspected M tuberculosis infection.

A biopsy for localized or disseminated skin lesions should be performed. Specimens for AFB and fungal cultures should be sent, as well as histopathology. The microbiology laboratory needs to be alerted of the concern for atypical organisms since the organism can be overlooked as a pathogen.

Abscess drainage

Fluid from a localized abscess should be obtained for culture; this method is preferred over swab culture of a draining abscess, sinus tract, or fistula.

Fine-needle aspiration and biopsy should be attempted on lymphadenitis for histopathology, cytology, and culture.


Histologic Findings

Histologic findings may reveal acute inflammation, microabscesses, granulomas (with or without caseation), and/or diffuse granulomatous inflammation. Special tissue stains for AFB may or may not reveal organisms.



There is no formal staging classification for M chelonae. Isolates represent either contamination, colonization, or true infection. When present, infections are either localized or disseminated.

Contributor Information and Disclosures

Alfred Scott Lea, MD Associate Professor of Medicine, Department of Medicine, Division of Infectious Diseases, University of Texas Medical Branch School of Medicine

Alfred Scott Lea, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, Infectious Diseases Society of America, Texas Medical Association, Harris County Medical Society, American College of Certified Wound Specialists

Disclosure: Nothing to disclose.


Jeana L Benwill, MD Assistant Professor, The University of Texas Health Science Center at Tyler

Jeana L Benwill, MD is a member of the following medical societies: Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Aaron Glatt, MD Chief Administrative Officer, Executive Vice President, Mercy Medical Center, Catholic Health Services of Long Island

Aaron Glatt, MD is a member of the following medical societies: American College of Chest Physicians, American Association for Physician Leadership, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Medical Association, American Society for Microbiology, American Thoracic Society, American Venereal Disease Association, Infectious Diseases Society of America, International AIDS Society, Society for Healthcare Epidemiology of America

Disclosure: Nothing to disclose.

Chief Editor

Michael Stuart Bronze, MD David Ross Boyd Professor and Chairman, Department of Medicine, Stewart G Wolf Endowed Chair in Internal Medicine, Department of Medicine, University of Oklahoma Health Science Center; Master of the American College of Physicians; Fellow, Infectious Diseases Society of America

Michael Stuart Bronze, MD is a member of the following medical societies: Alpha Omega Alpha, American Medical Association, Oklahoma State Medical Association, Southern Society for Clinical Investigation, Association of Professors of Medicine, American College of Physicians, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Klaus-Dieter Lessnau, MD, FCCP Clinical Associate Professor of Medicine, New York University School of Medicine; Medical Director, Pulmonary Physiology Laboratory; Director of Research in Pulmonary Medicine, Department of Medicine, Section of Pulmonary Medicine, Lenox Hill Hospital

Klaus-Dieter Lessnau, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, Society of Critical Care Medicine

Disclosure: Nothing to disclose.

  1. Brown-Elliott BA, Wallace RJ Jr. Clinical and taxonomic status of pathogenic nonpigmented or late-pigmenting rapidly growing mycobacteria. Clin Microbiol Rev. 2002 Oct. 15(4):716-46. [Medline]. [Full Text].

  2. Kusunoki S, Ezaki T. Proposal of Mycobacterium peregrinum sp. nov., nom. rev., and elevation of Mycobacterium chelonae subsp. abscessus (Kubica et al.) to species status: Mycobacterium abscessus comb. nov. Int J Syst Bacteriol. 1992 Apr. 42(2):240-5. [Medline].

  3. Lévy-Frébault V, Grimont F, Grimont PAD, et al. Deoxyribonucleic acid relatedness study of the Mycobacterium fortuitum-Mycobacterium chelonae complex. Int J System Bacteriol. 1986 Jul. 36:458-60. [Full Text].

  4. Adékambi T, Berger P, Raoult D, Drancourt M. rpoB gene sequence-based characterization of emerging non-tuberculous mycobacteria with descriptions of Mycobacterium bolletii sp. nov., Mycobacterium phocaicum sp. nov. and Mycobacterium aubagnense sp. nov. Int J Syst Evol Microbiol. 2006 Jan. 56(Pt 1):133-43. [Medline].

  5. Adékambi T, Reynaud-Gaubert M, Greub G, Gevaudan MJ, La Scola B, Raoult D, et al. Amoebal coculture of "Mycobacterium massiliense" sp. nov. from the sputum of a patient with hemoptoic pneumonia. J Clin Microbiol. 2004 Dec. 42(12):5493-501. [Medline]. [Full Text].

  6. Nash KA, Brown-Elliott BA, Wallace RJ Jr. A novel gene, erm(41), confers inducible macrolide resistance to clinical isolates of Mycobacterium abscessus but is absent from Mycobacterium chelonae. Antimicrob Agents Chemother. 2009 Apr. 53(4):1367-76. [Medline]. [Full Text].

  7. Ebani VV, Fratini F, Bertelloni F, Cerri D, Tortoli E. Isolation and identification of mycobacteria from captive reptiles. Res Vet Sci. 2012 Dec. 93(3):1136-8. [Medline].

  8. Williams MM, Yakrus MA, Arduino MJ, Cooksey RC, Crane CB, Banerjee SN, et al. Structural analysis of biofilm formation by rapidly and slowly growing nontuberculous mycobacteria. Appl Environ Microbiol. 2009 Apr. 75(7):2091-8. [Medline]. [Full Text].

  9. Hall-Stoodley L, Keevil CW, Lappin-Scott HM. Mycobacterium fortuitum and Mycobacterium chelonae biofilm formation under high and low nutrient conditions. J Appl Microbiol. 1998 Dec. 85 Suppl 1:60S-69S. [Medline].

  10. Svetlíková Z, Skovierová H, Niederweis M, Gaillard JL, McDonnell G, Jackson M. Role of porins in the susceptibility of Mycobacterium smegmatis and Mycobacterium chelonae to aldehyde-based disinfectants and drugs. Antimicrob Agents Chemother. 2009 Sep. 53(9):4015-8. [Medline].

  11. Falkinham JO 3rd. Nontuberculous mycobacteria from household plumbing of patients with nontuberculous mycobacteria disease. Emerg Infect Dis. 2011 Mar. 17(3):419-24. [Medline].

  12. Wallace RJ Jr, Brown BA, Onyi GO. Skin, soft tissue, and bone infections due to Mycobacterium chelonae chelonae: importance of prior corticosteroid therapy, frequency of disseminated infections, and resistance to oral antimicrobials other than clarithromycin. J Infect Dis. 1992 Aug. 166(2):405-12. [Medline].

  13. Kothavade RJ, Dhurat RS, Mishra SN, Kothavade UR. Clinical and laboratory aspects of the diagnosis and management of cutaneous and subcutaneous infections caused by rapidly growing mycobacteria. Eur J Clin Microbiol Infect Dis. 2012 Nov 9. [Medline].

  14. Hay RJ. Mycobacterium chelonae--a growing problem in soft tissue infection. Curr Opin Infect Dis. 2009 Apr. 22(2):99-101. [Medline].

  15. Kennedy BS, Bedard B, Younge M, Tuttle D, Ammerman E, Ricci J, et al. Outbreak of Mycobacterium chelonae infection associated with tattoo ink. N Engl J Med. 2012 Sep 13. 367(11):1020-4. [Medline].

  16. Winthrop KL, Chang E, Yamashita S, Iademarco MF, LoBue PA. Nontuberculous mycobacteria infections and anti-tumor necrosis factor-alpha therapy. Emerg Infect Dis. 2009 Oct. 15(10):1556-61. [Medline]. [Full Text].

  17. Uslan DZ, Kowalski TJ, Wengenack NL, Virk A, Wilson JW. Skin and soft tissue infections due to rapidly growing mycobacteria: comparison of clinical features, treatment, and susceptibility. Arch Dermatol. 2006 Oct. 142(10):1287-92. [Medline].

  18. Phillips MS, von Reyn CF. Nosocomial infections due to nontuberculous mycobacteria. Clin Infect Dis. 2001 Oct 15. 33(8):1363-74. [Medline].

  19. Mycobacterium chelonae infections associated with face lifts--New Jersey, 2002-2003. MMWR Morb Mortal Wkly Rep. 2004 Mar 12. 53(9):192-4. [Medline].

  20. Correa NE, Cataño JC, Mejía GI, Realpe T, Orozco B, Estrada S, et al. Outbreak of mesotherapy-associated cutaneous infections caused by Mycobacterium chelonae in Colombia. Jpn J Infect Dis. 2010 Mar. 63(2):143-5. [Medline].

  21. Song Y, Wu J, Yan H, Chen J. Peritoneal dialysis-associated nontuberculous mycobacterium peritonitis: a systematic review of reported cases. Nephrol Dial Transplant. 2012 Apr. 27(4):1639-44. [Medline].

  22. Moorthy RS, Valluri S, Rao NA. Nontuberculous mycobacterial ocular and adnexal infections. Surv Ophthalmol. 2012 May-Jun. 57(3):202-35. [Medline].

  23. Girgis DO, Karp CL, Miller D. Ocular infections caused by non-tuberculous mycobacteria: update on epidemiology and management. Clin Experiment Ophthalmol. 2012 Jul. 40(5):467-75. [Medline].

  24. Griffith DE, Girard WM, Wallace RJ Jr. Clinical features of pulmonary disease caused by rapidly growing mycobacteria. An analysis of 154 patients. Am Rev Respir Dis. 1993 May. 147(5):1271-8. [Medline].

  25. [Guideline] Griffith DE, Aksamit T, Brown-Elliott BA, Catanzaro A, Daley C, Gordin F, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am J Respir Crit Care Med. 2007 Feb 15. 175(4):367-416. [Medline].

  26. Mateo L, Rufí G, Nolla JM, Alcaide F. Mycobacterium chelonae tenosynovitis of the hand. Semin Arthritis Rheum. 2004 Dec. 34(3):617-22. [Medline].

  27. Eid AJ, Berbari EF, Sia IG, Wengenack NL, Osmon DR, Razonable RR. Prosthetic joint infection due to rapidly growing mycobacteria: report of 8 cases and review of the literature. Clin Infect Dis. 2007 Sep 15. 45(6):687-94. [Medline].

  28. Suh JD, Ramakrishnan VR, Tajudeen B, Reger C, Kennedy DW, Chiu AG. Identification and treatment of nontuberculous Mycobacterium sinusitis. Am J Rhinol Allergy. 2011 Nov-Dec. 25(6):421-4. [Medline].

  29. Brown-Elliott BA, Nash KA, Wallace RJ Jr. Antimicrobial susceptibility testing, drug resistance mechanisms, and therapy of infections with nontuberculous mycobacteria. Clin Microbiol Rev. 2012 Jul. 25(3):545-82. [Medline]. [Full Text].

  30. Browne SK, Burbelo PD, Chetchotisakd P, Suputtamongkol Y, Kiertiburanakul S, Shaw PA, et al. Adult-onset immunodeficiency in Thailand and Taiwan. N Engl J Med. 2012 Aug 23. 367(8):725-34. [Medline].

  31. O'Brien RJ, Geiter LJ, Snider DE Jr. The epidemiology of nontuberculous mycobacterial diseases in the United States. Results from a national survey. Am Rev Respir Dis. 1987 May. 135(5):1007-14. [Medline].

  32. Billinger ME, Olivier KN, Viboud C, de Oca RM, Steiner C, Holland SM, et al. Nontuberculous mycobacteria-associated lung disease in hospitalized persons, United States, 1998-2005. Emerg Infect Dis. 2009 Oct. 15(10):1562-9. [Medline]. [Full Text].

  33. Cassidy PM, Hedberg K, Saulson A, McNelly E, Winthrop KL. Nontuberculous mycobacterial disease prevalence and risk factors: a changing epidemiology. Clin Infect Dis. 2009 Dec 15. 49(12):e124-9. [Medline].

  34. Marras TK, Daley CL. Epidemiology of human pulmonary infection with nontuberculous mycobacteria. Clin Chest Med. 2002 Sep. 23(3):553-67. [Medline].

  35. Koh WJ, Kwon OJ, Jeon K, Kim TS, Lee KS, Park YK, et al. Clinical significance of nontuberculous mycobacteria isolated from respiratory specimens in Korea. Chest. 2006 Feb. 129(2):341-8. [Medline].

  36. Haverkort F. National atypical mycobacteria survey, 2000. Commun Dis Intell. 2003. 27(2):180-9. [Medline].

  37. Yu JA, Weyant MJ, Mitchell JD. Surgical treatment of atypical mycobacterial infections. Thorac Surg Clin. 2012 Aug. 22(3):277-85. [Medline].

  38. Vemulapalli RK, Cantey JR, Steed LL, Knapp TL, Thielman NM. Emergence of resistance to clarithromycin during treatment of disseminated cutaneous Mycobacterium chelonae infection: case report and literature review. J Infect. 2001 Oct. 43(3):163-8. [Medline].

  39. Brown-Elliott BA, Mann LB, Hail D, Whitney C, Wallace RJ Jr. Antimicrobial susceptibility of nontuberculous mycobacteria from eye infections. Cornea. 2012 Aug. 31(8):900-6. [Medline].

  40. Wallace RJ Jr, Swenson JM, Silcox VA, Bullen MG. Treatment of nonpulmonary infections due to Mycobacterium fortuitum and Mycobacterium chelonei on the basis of in vitro susceptibilities. J Infect Dis. 1985 Sep. 152(3):500-14. [Medline].

  41. Wallace RJ Jr, Brown-Elliott BA, Crist CJ, Mann L, Wilson RW. Comparison of the in vitro activity of the glycylcycline tigecycline (formerly GAR-936) with those of tetracycline, minocycline, and doxycycline against isolates of nontuberculous mycobacteria. Antimicrob Agents Chemother. 2002 Oct. 46(10):3164-7. [Medline]. [Full Text].

  42. Peres E, Khaled Y, Krijanovski OI, Mineishi S, Levine JE, Kaul DR, et al. Mycobacterium chelonae necrotizing pneumonia after allogeneic hematopoietic stem cell transplant: report of clinical response to treatment with tigecycline. Transpl Infect Dis. 2009 Feb. 11(1):57-63. [Medline].

  43. Wallace RJ Jr, Brown-Elliott BA, Ward SC, Crist CJ, Mann LB, Wilson RW. Activities of linezolid against rapidly growing mycobacteria. Antimicrob Agents Chemother. 2001 Mar. 45(3):764-7. [Medline]. [Full Text].

  44. Brown-Elliott BA, Wallace RJ Jr, Blinkhorn R, Crist CJ, Mann LB. Successful treatment of disseminated Mycobacterium chelonae infection with linezolid. Clin Infect Dis. 2001 Oct 15. 33(8):1433-4. [Medline].

  45. Kyle SD, Porter WM. Mycobacterium chelonae infection successfully treated with oral clarithromycin and linezolid. Br J Dermatol. 2004 Nov. 151(5):1101. [Medline].

  46. van Ingen J, Totten SE, Helstrom NK, Heifets LB, Boeree MJ, Daley CL. In vitro synergy between clofazimine and amikacin in treatment of nontuberculous mycobacterial disease. Antimicrob Agents Chemother. 2012 Dec. 56(12):6324-7. [Medline]. [Full Text].

  47. Peloquin CA, Berning SE, Nitta AT, Simone PM, Goble M, Huitt GA, et al. Aminoglycoside toxicity: daily versus thrice-weekly dosing for treatment of mycobacterial diseases. Clin Infect Dis. 2004 Jun 1. 38(11):1538-44. [Medline].

  48. Pinto-Gouveia M, Gameiro A, Ramos L, Cardoso JC, Brites MM, Tellechea Ó, et al. Mycobacterium chelonae Is an Ubiquitous Atypical Mycobacterium. Case Rep Dermatol. 2015 May-Aug. 7 (2):207-11. [Medline].

Cutaneous lesions from Mycobacterium abscessus. Courtesy of K. Galil, US Centers for Disease Control and Prevention.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.