Table 1.

MICs of ampicillin, oxyiminocephalosporins, carbapenems, and other antibiotics for E. coli TG1 and the bacterial clinical isolate expressing the IMP-1 and IMP-28 β-lactamases

Antibiotic	MIC (μg/ml)a for:
	K. oxytoca HGUGM21530 (IMP-28)	E. coli TG1 PBGS18-pCTX IMP-28	E. coli TG1 PBGS18-pCTX IMP-1	E. coli TG1 PBGS18-pCTX
Ampicillin	32	64	512	2
Cefoxitin	256	256	1,028	1
Cefotaxime	64	256	256	0.06
Ceftazidime	64	128	512	0.06
Cefepime	2	32	128	<0.12
Aztreonam	<0.25	<0.25	<0.25	<0.25
Imipenem	1	0.5	2	0.12
Meropenem	1	4	16	<0.03

^aThe results were confirmed in three independent experiments.