TABLE 1.

AMK MICs and time-kill responses among CR-Kp strains

K. pneumoniae strain no.	KPC subtype	MIC (μg/ml)a			AMK log kill at 24 h (CFU/ml)b			Regrowth at 4× MIC
		AMK	GEN	TOB	0.25× MIC	1× MIC	4× MIC
615	KPC-2	4	4	16	4.10	−5.97	−5.41	No
383	KPC-2	16	0.5	16	6.93	−0.49	−5.28	No
871	KPC-2	16	1	16	2.76	3.66	−5.81	No
930	KPC-3	16	1	8	2.95	2.71	−5.81	No
1	KPC-2	16	64	>64	3.80	−0.18	−5.82	No
136	KPC-3	16	>64	>64	3.64	3.42	−5.46	No
294	KPC-2	16	64	>64	3.66	0.63	−5.56	No
584	KPC-2	16	32	>64	3.84	−4.00	−5.15	No
928	KPC-3	16	64	>64	2.57	0.96	−6.02	No
184	KPC-2	32	2	32	4.05	3.20	−2.78	Yes
216	KPC-2	32	1	32	3.81	3.12	0.44	Yes
484	KPC-2	32	1	32	3.49	−4.59	−5.57	No
539	KPC-2	32	2	16	4.07	4.35	−3.12	Yes
587	KPC-2	32	1	16	3.52	−0.01	−5.89	No
669	KPC-2	32	2	32	3.53	3.21	−5.85	No
705	KPC-2	32	0.5	32	2.35	−3.75	−5.77	No
709	KPC-2	32	1	16	3.36	−5.79	−5.32	No
94	KPC-2	32	64	>64	3.59	−2.08	−5.40	No
649	KPC-2	32	32	32	3.94	−5.04	−5.53	No
692	KPC-2	32	64	32	3.46	3.35	−5.78	No

^aAMK, amikacin; GEN, gentamicin; TOB, tobramycin.

^bBoldface numbers indicate bactericidal (≥3-log decrease in CFU/ml from the starting inoculum) killing without regrowth.