TABLE 5.

Suggested broth microdilution breakpoints for susceptibility testing of RGMa

DrugMIC (μg/ml) for category:
SusceptibleIntermediateResistant
Recommended test drugsa
    Amikacin≤1632≥64
    Cefoxitin≤1632-64≥128
    Ciprofloxacin≤12≥4
    Clarithromycin≤24≥8
    Doxycycline≤12-8≥16
    Imipenemb≤48≥16
    Sulfamethoxazolec≤32≥64
    Tobramycind≤48≥16
Secondary test drugse
    Cefmetazole≤1632≥64
    Gatifloxacin≤24≥8
    Levofloxacin≤24≥8
    Linezolid≤816≥32
    Moxifloxacin≤12≥4
    Vancomycin≤48-16≥32
  • a Drugs and breakpoints recommended by NCCLS document M24-T2 (218).

  • b Imipenem MICs are not reported for M. chelonae-abscessus group isolates due to lack of reproducibility.

  • c MIC end point is 80% inhibition of growth (218).

  • d Tobramycin MICs recommended to be reported only for isolates of M. chelonae.

  • e Non-NCCLS-approved mycobacterial drugs and their breakpoints. Breakpoints are those recommended for aerobic organisms in NCCLS M100-S11, 2001 (112), except those for linezolid, which were recently proposed for mycobacteria by Wallace et al. (195).