TABLE 3.

MIC assay of E. coli DH10B cells with pBC SK(+) phagemid harboring bla_IMP variant genes as well as controls (phagemid without a bla gene and no phagemid)^a

β-Lactam	MIC (μg/ml) for E. coli DH10B
	pBC SK(+)-blaIMP-1-V67A	pBC SK(+)-blaIMP-1 (V67)	pBC SK(+)-blaIMP-1-V67I	pBC SK(+)-blaIMP-10 (F67)	pBC SK(+)	No phagemid
Cephalothin	1,024	512	1,024	1,024	16	16
Cefotaxime	256	256	128	512	0.125	0.25
Ceftazidime	128	256	512	1,024	0.5	0.5
Cefoxitin	1,024	1,024	1,024	512	8	16
Benzylpenicillin	32	256	128	64	32	32
Ampicillin	16	256	256	32	4	8
Imipenem	8	4	16	16	0.25	0.25
Meropenem	32	16	16	128	<0.0625	0.0625
Doripenem	8	16	8	128	0.0625	0.125
Aztreonam	0.125	0.25	0.125	0.25	0.25	0.25

^aAmino acid identities are shown in bold. Data for bla_IMP-1, pBC SK(+), and no phagemid are from reference 33.