Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Microbiology of nontuberculous mycobacteria

David E Griffith, MD
Section Editor
C Fordham von Reyn, MD
Deputy Editor
Allyson Bloom, MD


Mycobacterial species other than Mycobacterium tuberculosis and Mycobacterium leprae are generally free-living organisms that are ubiquitous in the environment. They have been recovered from water, soil, domestic and wild animals, milk, and food [1-4]. As the incidence of tuberculosis (TB) declined in areas of the world where socioeconomic conditions were rapidly advancing, the frequency of isolating nontuberculous mycobacteria (NTM) began to increase, and their relevance to human disease became apparent [5].

In 1959, Runyon proposed the first classification system for these organisms that divided human isolates of NTM into four groups on the basis of growth rates, colony morphology, and pigmentation in the presence and absence of light (table 1) [6]. Though now outdated, this classification allowed mycobacterial laboratories to more readily identify individual species of NTM, resulting in clearer characterization of distinct diseases or syndromes associated with these organisms.

With the availability of 16S ribosomal DNA sequencing and high-performance liquid chromatography (HPLC), and polymerase chain reaction-restriction length polymorphism analysis (PRA), the number of new species of NTM has risen dramatically with the naming of species such as Mycobacterium genavense, Mycobacterium interjectum, Mycobacterium triplex, Mycobacterium celatum, and Mycobacterium lentiflavum. Over 160 species have been recognized in the genus Mycobacterium [7].

The microbiology of NTM will be reviewed here. Other issues related to NTM are discussed separately. (See "Diagnosis of nontuberculous mycobacterial infections of the lungs in HIV-negative patients" and "Pathogenesis of nontuberculous mycobacterial infections" and "Treatment of nontuberculous mycobacterial infections of the lung in HIV-negative patients".)


Within the genus Mycobacterium, four groups of human pathogens can be delineated on the basis of microbiologic, clinical, and epidemiologic characteristics (table 1):


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Sep 2016. | This topic last updated: Aug 18, 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. Wolinsky E, Rynearson TK. Mycobacteria in soil and their relation to disease-associated strains. Am Rev Respir Dis 1968; 97:1032.
  2. Chapman JS. The ecology of the atypicalmycobacteria. Arch Environ Health 1971; 22:41.
  3. Goslee S, Wolinsky E. Water as a source of potentially pathogenic mycobacteria. Am Rev Respir Dis 1976; 113:287.
  4. Gruft H, Falkinham JO 3rd, Parker BC. Recent experience in the epidemiology of disease caused by atypical mycobacteria. Rev Infect Dis 1981; 3:990.
  5. Wolinsky E. Nontuberculous mycobacteria and associated diseases. Am Rev Respir Dis 1979; 119:107.
  6. RUNYON EH. Anonymous mycobacteria in pulmonary disease. Med Clin North Am 1959; 43:273.
  7. Brown-Elliott BA, Griffith DE, Wallace RJ Jr. Newly described or emerging human species of nontuberculous mycobacteria. Infect Dis Clin North Am 2002; 16:187.
  8. Griffith DE, Brown-Elliott BA, Benwill JL, Wallace RJ Jr. Mycobacterium abscessus. "Pleased to meet you, hope you guess my name...". Ann Am Thorac Soc 2015; 12:436.
  9. NCCLS (formerly National Committee for Clinical Laboratory Standards) Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard (M24-A) 2003.
  10. Tortoli E. Microbiological features and clinical relevance of new species of the genus Mycobacterium. Clin Microbiol Rev 2014; 27:727.
  11. Griffith DE, Brown-Elliott BA, Wallace RJ Jr. Hit the Road, MAC, and Don't You Come Back No More. Am J Respir Crit Care Med 2015; 191:1222.
  12. Woodley CL, Kilburn JO. In vitro susceptibility of Mycobacterium avium complex and Mycobacterium tuberculosis strains to a spiro-piperidyl rifamycin. Am Rev Respir Dis 1982; 126:586.
  13. Ahn CH, Ahn SS, Anderson RA, et al. A four-drug regimen for initial treatment of cavitary disease caused by Mycobacterium avium complex. Am Rev Respir Dis 1986; 134:438.
  14. Griffith DE, Aksamit T, Brown-Elliott BA, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am J Respir Crit Care Med 2007; 175:367.
  15. Brown-Elliott BA, Iakhiaeva E, Griffith DE, et al. In vitro activity of amikacin against isolates of Mycobacterium avium complex with proposed MIC breakpoints and finding of a 16S rRNA gene mutation in treated isolates. J Clin Microbiol 2013; 51:3389.
  16. Diagnosis and treatment of disease caused by nontuberculous mycobacteria. This official statement of the American Thoracic Society was approved by the Board of Directors, March 1997. Medical Section of the American Lung Association. Am J Respir Crit Care Med 1997; 156:S1.
  17. Heifets LB, Iseman MD. Individualized therapy versus standard regimens in the treatment of Mycobacterium avium infections. Am Rev Respir Dis 1991; 144:1.
  18. Steadham JE. High-catalase strains of Mycobacterium kansasii isolated from water in Texas. J Clin Microbiol 1980; 11:496.
  19. Good RC, Silcox VA, Kilburn JO, et al. Identification and drug susceptibility test results from mycobacterial spp. Clin Microbiol Newsletter 1985; 7:133.
  20. Brown-Elliott BA, Wallace RJ Jr. Clinical and taxonomic status of pathogenic nonpigmented or late-pigmenting rapidly growing mycobacteria. Clin Microbiol Rev 2002; 15:716.
  21. Chapman J. The Atypical Mycobacteria, Plenum Publishing, New York 1977.
  22. Silcox VA, Good RC, Floyd MM. Identification of clinically significant Mycobacterium fortuitum complex isolates. J Clin Microbiol 1981; 14:686.
  23. Swenson JM, Wallace RJ Jr, Silcox VA, Thornsberry C. Antimicrobial susceptibility of five subgroups of Mycobacterium fortuitum and Mycobacterium chelonae. Antimicrob Agents Chemother 1985; 28:807.
  24. Diagnosis and treatment of disease caused by nontuberculous mycobacteria. Am Rev Respir Dis 1990; 142:940.
  25. Brown BA, Wallace RJ Jr, Onyi GO, et al. Activities of four macrolides, including clarithromycin, against Mycobacterium fortuitum, Mycobacterium chelonae, and M. chelonae-like organisms. Antimicrob Agents Chemother 1992; 36:180.
  26. Nash KA, Zhang Y, Brown-Elliott BA, Wallace RJ Jr. Molecular basis of intrinsic macrolide resistance in clinical isolates of Mycobacterium fortuitum. J Antimicrob Chemother 2005; 55:170.
  27. 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; 53:1367.
  28. Brown-Elliott BA, Vasireddy S, Vasireddy R, et al. Utility of sequencing the erm(41) gene in isolates of Mycobacterium abscessus subsp. abscessus with low and intermediate clarithromycin MICs. J Clin Microbiol 2015; 53:1211.