Table 3. Antibiotic susceptibility profile of NDM-1-producing Enterobacteriaceae with breakpoints (mg/L).

Patient number (organism)	AMK (16)	ATM (4)	FEP (8)	FOX (8)	CTX (1)	TZP (4)	CIP (1)	CST (2)	ETP (0.5)	GEN (4)	IPM (1)	MEM (1)	TGC (2)
1 (E. coli)	256	24	64	256	256	256	32	0.5	8	1024	32	32	1
2(M. morgannii)	256	256	256	256	256	256	32	256	4	1024	16	12	4
3(K. pneumoniae)	24	24	256	256	256	256	32	.125	32	0.125	32	32	0.75
4 (E. coli)	256	256	96	256	256	256	>32	0.125	>32	1024	1.5	32	0.25
5(K. pneumoniae)	256	256	256	256	256	256	>32	0.38	>32	512	32	32	1.5
6(K. pneumoniae)	4	64	256	256	256	256	1	0.75	>32	2	>32	>32	1
7 (P. stuartii)	1.5	0.25	0.25	256	256	1.5	1.5	256	3	0.125	1	1.5	2
8(K. pneumoniae)	16	96	256	256	256	256	0.19	0.38	16	1	32	6	0.75
9 (E. coli)	3	0.064	256	256	256	256	>32	0.25	>32	24	4	12	0.5
10 (Enterobacter cloacae)	>256	128	32	256	256	256	12	0.38	>32	1024	32	32	3
11(K. pneumoniae)	16	128	64	256	256	256	32	4	>32	3	>32	24	16
12(K. pneumoniae)	16	96	256	256	256	256	32	0.75	32	3	>32	>32	8
13(K. pneumoniae)	256	256	128	256	256	256	16	0.25	>32	512	>32	>32	0.5
14(K. pneumoniae)	128	128	256	256	256	256	32	0.38	>32	64	>32	>32	4
15(K. pneumoniae)	16	128	256	256	256	256	16	0.25	>32	64	16	16	0.5
16 (E. coli)	128	256	256	256	256	256	32	0.38	>32	64	>32	>32	8
17(K. pneumoniae)	32	256	256	256	256	256	32	0.125	>32	0.125	>32	>32	4
18(K. pneumoniae)	64	128	256	256	256	256	16	0.38	>32	64	>32	>32	0.5
19(K. pneumoniae)	32	128	256	256	256	256	32	48	>32	128	>32	>32	16
20(K. pneumoniae)	128	256	256	256	256	256	16	1.5	>32	512	>32	>32	4
21(K. pneumoniae)	64	128	256	256	256	256	32	0.38	>32	128	>32	>32	2

The values in parenthesis in the first row are the recommended breakpoints for resistance according to CLSI [11]. AMK = amikacin; ATM = aztreonam; FEP = cefepime; FOX = cefoxitin; CTX = cefotaxime; TZP = piperacillin-tazobactam; CIP = ciprofloxacin; CST = colistin; ETP = ertapenem; GEN = gentamicin; IPM = imipenem; MEM = meropenem; TGC = tigecycline.