In Vitro Susceptibility of Mycobacterium abscessus and Mycobacterium fortuitum Isolates to 30 Antibiotics

Table 1

The drug susceptibility results of 37 RGM isolates.

Antimicrobial Agent	MIC(g/ml)		M. abscessus (n=20)			MIC(g/ml)		M. fortuitum (n=17)
	range	MIC 90	R	I	S	range	MIC 90	R	I	S
Macrolides
CLR	0.0625-64	32	4 (20%)/7(35%)	0 (0%)/0 (0%)	16 (80%)/13(65%)	32-64	32	16 (94%)/17(100%)	0 (0%)/0 (0%)	1 (6%)/0(0%)
AZM	0.125-128	2	2 (10%)	0 (0%)	18 (90%)	8-128	32	17 (100%)	0 (0%)	0 (0%)
Rifamycins
RFB	0.5-8	4	15 (75%)	-	5 (25%)	1-8	4	16 (94%)	-	1 (6%)
RIF	64-256	128	20 (100%)	-	0 (0%)	32-256	128	17 (100%)	-	0 (0%)
Aminoglycosides
STR	32-128	64	20 (100%)	-	0 (0%)	16-128	32	17 (100%)	-	0 (0%)
GEN	0.5-64	32	14 (70%)	1 (5%)	5 (25%)	4-64	32	4 (24%)	9 (53%)	4 (24%)
KAN	4-16	8	16 (80%)	-	4 (20%)	4-32	16	16 (94%)	-	1 (6%)
TOB	2-32	8	12 (60%)	3 (15%)	5 (25%)	16-64	16	0 (0%)	0 (0%)	17 (100%)
NEO	0.5-64	16	13 (65%)	-	7 (35%)	2-8	2	0 (0%)	-	17 (100%)
AMK	0.5-64	32	2 (10%)	9 (45%)	9 (45%)	2-8	4	0 (0%)	0 (0%)	17 (100%)
Fluoroquinolones
MXF	0.0625-16	8	19 (95%)	0 (0%)	1 (5%)	0.0625-8	2	10 (59%)	5 (29%)	2 (12%)
CIP	0.125-128	64	19 (95%)	0 (0%)	1 (5%)	0.125-256	128	8 (47%)	0 (0%)	9 (53%)
LVX	0.125-32	16	19 (95%)	0 (0%)	1 (5%)	0.125-32	16	7 (41%)	0 (0%)	10 (59%)
Cephalosporins
FOX	16-256	64	2 (10%)	10 (50%)	8 (40%)	16-128	32	15 (88%)	0 (0%)	2 (12%)
CMZ	2-256	128	11 (55%)	5 (25%)	4 (20%)	2-64	8	2 (12%)	0 (0%)	15 (88%)
Tetracyclines
TCY	2-256	64	9 (45%)	3 (15%)	8 (40%)	1-8	4	0 (0%)	12 (70%)	5 (30%)
DOX	0.5-256	128	14 (70%)	2 (10%)	4 (20%)	0.5-256	128	15 (88%)	0 (0%)	2 (12%)
MNO	0.125-128	64	11 (55%)	3 (15%)	6 (30%)	0.25-32	16	14 (82%)	1 (6%)	2 (12%)
Glycylcycline
TGC	0.0625-16	8	8 (40%)	6 (30%)	6 (30%)	0.0625-4	0.5	0 (0%)	1 (6%)	16 (94%)
Sulfonamides
SOX	2-256	128	18 (90%)	-	2 (10%)	16-256	128	14 (82%)	-	3 (18%)
Carbapenems
IMP	1-256	64	13 (65%)	2 (10%)	5 (25%)	2-32	16	2 (12%)	12 (70%)	3 (18%)
Oxazolidinones
LNZ	2-128	16	3 (15%)	1 (5%)	16 (80%)	8-32	16	3 (18%)	12 (70%)	2 (12%)
Lincosamides
CLI	8-256	128	20 (100%)	0 (0%)	0 (0%)	256	256	17 (100%)	0 (0%)	0 (0%)
Penicillins
OXA	256	256	20 (100%)	-	0 (0%)	256	256	17 (100%)	-	0 (0%)
Polypeptides
TEC	0.5-256	128	17 (85%)	1 (5%)	2 (10%)	128-256	128	17 (100%)	0 (0%)	0 (0%)
VAN	256	256	20 (100%)	0 (0%)	0 (0%)	256	256	17 (100%)	0 (0%)	0 (0%)
Others
CFZ	0.25-128	32	19 (95%)	-	1 (5%)	0.125-128	0.25	10 (59%)	-	7 (41%)
EMB	256	256	20 (100%)	-	0 (0%)	256	256	17 (100%)	-	0 (0%)
INH	8-256	16	20 (100%)	-	0 (0%)	8-16	8	17 (100%)	-	0 (0%)
ETH	16-256	64	20 (100%)	-	0 (0%)	4-256	32	16 (94%)	-	1 (6%)

(a) CLR= clarithromycin, AZM= azithromycin, RFB= rifabutin, RIF= rifampin, STR= streptomycin, GEN= gentamycin, KAN= kanamycin, TOB= tobramycin, NEO= neomycin, AMK= amikacin, MXF= moxifloxacin, CIP= ciprofloxacin, LVX= levofloxacin, FOX= cefoxitin, CMZ= cefmetazole, TCY= tetracycline, DOX= doxycycline, MNO= minocycline, TGC= tigecycline, SOX= sulfamethoxazole, IMP= imipenem, LNZ= linezolid, CLI= clindamycin, OXA= oxacillin, TEC= teicoplanin, VAN= vancomycin, CFZ= clofazimine, EMB= ethambutol, INH= isoniazid, and ETH= ethionamide.
(b) “-“ indicates data not available.
(c) For CLR, each resistance and susceptible rate has two data. The first is the MIC result for 3 days and the second is the MIC result for 14 days.