TABLE 1.

In vitro potency of piperacillin-tazobactam and commercially available antibiotics against each E. coli isolate

E. coli isolate	MIC (μg/ml) fora:
	TZP	Antibiotic
		FEP	CRO	CAZ	CIP	CST	ATM	ETP	IPM	MEM	TOB
C2-9	512	0.25	0.125	1	≥32	0.5	0.25	≤0.015	0.125	≤0.06	8
C3-23	≥2,048	1	≤0.06	2	1	1	0.5	0.03	0.125	≤0.06	1
C6-25	2,048	0.5	0.125	1	≥32	0.5	0.25	0.03	0.25	≤0.06	2
C7-1	256	0.5	≤0.06	2	≤0.015	1	1	0.125	0.25	≤0.06	2
C10-11	≥2,048	0.25	≤0.06	0.5	≤0.015	1	0.125	≤0.015	0.25	≤0.06	1
C11-14	≥2,048	0.5	0.125	1	≤0.015	1	0.25	0.06	0.5	≤0.06	1
C12-1	512	0.25	0.06	0.5	≤0.015	0.5	0.125	≤0.015	0.125	≤0.06	1
C14-26	≥2,048	8	0.5	4	0.5	0.5	1	2	0.5	0.25	2
C18-6	≥2,048	0.125	≤0.06	0.25	0.03	2	≤0.06	≤0.015	0.125	≤0.06	2
C30-5	256	0.125	≤0.06	0.25	≤0.015	0.5	0.125	≤0.015	0.5	≤0.06	8
C1-6	16	≤0.06	2	2	0.015	0.5	2	0.03	1	0.06	4
C1-7	4	0.125	≤0.06	0.5	8	0.5	≤0.06	≤0.015	0.25	≤0.06	4
C1-23	2	≤0.06	≤0.06	0.25	≤0.015	1	≤0.06	≤0.015	0.125	≤0.06	4
C2-5	4	0.125	0.25	0.5	16	0.5	0.5	≤0.015	0.125	≤0.06	1
C2-14	2	≤0.06	0.125	0.25	0.03	8	0.25	≤0.015	0.125	≤0.06	2
C2-19	4	≤0.06	≤0.06	2	≤0.015	0.5	2	≤0.015	0.125	≤0.06	0.5
C2-27	2	≤0.06	≤0.06	0.125	≤0.015	0.5	≤0.06	≤0.015	0.25	≤0.06	2
C3-2	4	0.125	≤0.06	0.5	0.06	0.5	0.125	≤0.015	0.125	≤0.06	2

^aTZP, piperacillin-tazobactam; FEP, cefepime; CRO, ceftriaxone; CAZ, ceftazidime; CIP, ciprofloxacin; CST, colistin; ATM, aztreonam; ETP, ertapenem; IPM, imipenem; MEM, meropenem; TOB, tobramycin.