Table 1.

Breakpoints used for RGM drug susceptibility testing by the broth dilution with antimicrobial concentration range for broth dilution and disc diffusion method^a

Antimicrobial	MIC (μg/ml) for broth dilution			Broth dilution range (μg/ml)	Disc diffusion content (μg)
	Susceptible	Intermediate	Resistant
AMIb	≤16	32	≥64	1–64	30
AUG2c	≤8/4	16/8	≥32/16	2/1–64/32	NA
FEPc	≤8	16	≥32	1–32	NA
FOXb	≤16	32–64	≥128	4–128	30
AXOc	≤8	16–32	≥64	4–64	NA
CIPb	≤1	2	≥4	0.12–4	5
CLAb	≤2	4	≥8	0.06–16	15
DOXb	≤1	2–8	≥16	0.12–16	30
IMIb	≤4	8	≥16	2–64	10
LZDb	≤8	16	≥32	1–32	10
MINc	≤1	2–4	≥8	1–8	30
MXFe	≤1	2	≥4	0.25–8	1
TGCd	NA	NA	NA	0.015–4	15
TOBb	≤4	8	≥16	1–4	10
SXTc	≤2/38	NA	≥4/76	0.25/4.75–8/152	NA

^aAMI, amikacin; AUG2, amoxicillin-clavulanic acid; FEP, cefepime; FOX, cefoxitin; AXO, ceftriaxone; CIP, ciprofloxacin; CLA, clarithromycin; DOX, doxycycline; IMI, imipenem; LZD, linezolid; MIN, minocycline; MXF, moxifloxacin; TOB, tobramycin; SXT, trimethoprim-sulfamethoxazole; NA, not tested by the disc diffusion method.

^bThese breakpoints are recommended by CLSI for rapidly growing mycobacteria (12).

^cThese breakpoints have not yet been established by CLSI for RGM. The values are recommended by CLSI for Nocardia and other Actinomycetes (12).

^dFor breakpoints for TGC, see Tables 4 and 5.

^eThese breakpoints are recommended by CLSI for Gram-positive bacteria (9).