Differences in drug susceptibility pattern between Mycobacterium avium and Mycobacterium intracellulare isolated in respiratory specimens

Eun Hye Cho, Hee Jae Huh, Dong Joon Song, Seong Mi Moon, Seung Heon Lee, So Youn Shin, Chang Ki Kim, Chang Seok Ki, Won Jung Koh, Nam Yong Lee

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5 Citations (Scopus)


Mycobacterium avium complex (MAC) is the most common etiologic organisms of nontuberculous mycobacteria (NTM) lung disease. In this study, we aimed to retrospectively investigate the differences in drug susceptibility patterns of two major MAC species; Mycobacterium avium and Mycobacterium intracellulare. A total of 1883 major two MAC isolates (1060 M. avium and 823 M. intracellulare) from respiratory specimens were included in this study during the period 2011─2016. The minimum inhibitory concentrations (MICs) were determined by broth microdilution method and MIC50/MIC90 values were derived from MIC distribution. M. intracellulare had generally low susceptible rates than M. avium for almost all tested antimicrobials except ethambutol and amikacin. The susceptible rate to clarithromycin was >94% of the MAC without significant differences between the two species. The MIC50 values of ciprofloxacin, clarithromycin, linezolid, moxifloxacin, and rifampicin were higher in M. intracellulare than in M. avium, contrary to the results of ethambutol with a higher MIC50 in M. avium. In general, M. intracellulare showed a higher resistance rate and higher MIC50 values than M. avium. Differences between this study and previous reports suggest regional differences in drug susceptibility profile of MAC species.

Original languageEnglish
Pages (from-to)315-318
Number of pages4
JournalJournal of Infection and Chemotherapy
Issue number4
Publication statusPublished - 2018 Apr 1
Externally publishedYes



  • Drug susceptibility test
  • Mycobacterium avium
  • Mycobacterium intracellulare
  • Nontuberculous mycobacteria

ASJC Scopus subject areas

  • Microbiology (medical)
  • Pharmacology (medical)
  • Infectious Diseases

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