TABLE 2.

MICs of β-lactams (Etest) for the S. enterica serotype Westhampton isolate 04CEB8273SAL, E. coli DH10B harboring natural plasmid pWES-1, E. coli DH5α harboring recombinant plasmid pCTX-M-53, E. coli DH5α harboring phagemid pBK-CMV, E. coli DH10B reference strain, and E. coli ATCC 25922 quality control strain

β-Lactam	MIC (μg/ml) for:
	Serotype Westhampton 04CEB8273SAL	E. coli DH10B(pWES-1)	E. coli DH5α(pCTX-M-53)	E. coli DH5α(pBK-CMV)	E. coli DH10B	E. coli ATCC 25922
Ampicillin	>256	>256	>256	2	4	4
Amoxicillin-clavulanic acida	8	8	8	4	8	8
Ticarcillin	>256	>256	>256	2	8	8
Ticarcillin-clavulanic acidb	128	32	32	2	2	4
Piperacillin	>256	>256	>256	1	2	2
Piperacillin-tazobactamc	16	4	2	1	4	2
Cefoxitin	8	4	4	2	4	2
Ceftazidime	>256	64	64	0.125	0.5	0.25
Ceftazidime-clavulanic acidd	2	0.5	0.125	0.125	0.5	0.125
Ceftriaxone	>256	>256	>256	<0.06	0.125	0.06
Cefotaxime-clavulanic acidd	1	0.125	0.06	<0.06	0.125	0.06
Cefepime	>32	32	>32	<0.06	0.125	0.06
Aztreonam	>256	128	128	<0.06	0.25	0.06
Imipenem	0.5	0.5	0.5	0.25	0.5	0.25

^a2:1 amoxicillin-clavulanic acid.

^b2 μg/ml clavulanic acid.

^c4 μg/ml tazobactam.

^d4 μg/ml clavulanic acid.