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Updated: Jun 10, 2026
Intradermal Inoculation of Mycobacterium avium in the Mouse Ear
Published on: July 3, 2025
[Susceptibility test of the Mycobacterium avium complex to sixteen anti-infective agents]
Hong-fei Duan1, Norio Doi, Qi Li
1Department of General Internal Medicine. Beijing Tuberculosis & Thoracic Tumor Research Institute, Beijing 101149, China.
Objective:
To compare the in vitro activities of 13 anti-infective agents and 3 new quinolones (sitafloxacin, gatifloxacin and moxifloxacin) against Mycobacterium avium complex (MAC) isolates, and therefore to explore the possibility of using these quinolones to treat MAC diseases.
Methods:
The minimal inhibitory concentration (MIC) of the above 16 anti-infective agents, including sitafloxacin, gatifloxacin and moxifloxacin against MAC isolates was determined by using agar dilution methods, and then the MIC90s of the different anti-infective agents were compared.
Results:
The MICs of M. avium isolates showed a wider range and was less sensitive to most of the anti-infective agents as compared with M. intracellulare isolates. The MIC90s of clarithromycin against M. avium and M. intracellulare isolates were 32 mg/L and 16 mg/L, respectively, which were the lowest among 4 macrolide compounds. The MIC90 of rifalazil were 0.5 mg/L and 0.25 mg/L, respectively, which were the lowest among 4 rifamycin compounds. The MIC90 of sitafloxacin against M. avium and M. intracellulare isolates were both 4 mg/L, which were the lowest among 5 quinolones. For gatifloxacin and moxifloxacin, the MIC90 against M. avium and M. intracellulare isolates were both 8 mg/L. Two clarithromycin-sensitive strains (MIC=0.5 mg/L) showed a similar MIC of the lower limit for other compounds. Three clarithromycin-insensitive strains (MIC=64 mg/L) showed a similar MIC of the upper limit for other compounds except quinolones.
Conclusion:
Rifalazil, sitafloxacin, gatifloxacin and moxifloxacin showed acceptable in vitro activities against MAC isolates.
