TABLE 1.

MICs of β-lactams for N. asteroides sensu stricto JPL, E. coli JM109 harboring recombinant plasmid pAST-1, and reference strain E. coli JM109

β-Lactama	MIC (μg/ml)
	N. asteroides JPL	E. coli JM109(pAST-1)	E. coli JM109
Amoxicillin	64	>512	2
Amoxicillin + CLA	4	32	2
Amoxicillin + TZB	64	>512	2
Amoxicillin + SUL	64	>512	2
Ticarcillin	256	256	2
Ticarcillin + CLA	8	8	1
Ticarcillin + TZB	128	256	1
Ticarcillin + SUL	256	256	2
Piperacillin	512	128	1
Piperacillin + CLA	32	4	0.5
Piperacillin + TZB	128	128	0.5
Piperacillin + SUL	256	128	0.5
Cephalothin	128	8	4
Cephalothin + CLA	64	4	2
Cephalothin + TZB	128	8	2
Cephalothin + SUL	128	8	2
Cefoxitin	128	4	4
Cefoxitin + CLA	64	4	4
Cefoxitin + TZB	64	4	4
Cefoxitin + SUL	64	4	4
Ceftazidime	>512	0.25	0.25
Ceftazidime + CLA	>512	0.25	0.25
Ceftazidime + TZB	>512	0.25	0.25
Ceftazidime + SUL	>512	0.25	0.25
Cefotaxime	<0.06	0.06	0.06
Cefotaxime + CLA	<0.06	0.06	0.06
Cefotaxime + TZB	<0.06	0.06	0.06
Cefotaxime + SUL	<0.06	0.06	0.06
Aztreonam	>512	0.12	0.12
Aztreonam + CLA	>512	0.12	0.06
Aztreonam + TZB	>512	0.12	0.06
Aztreonam + SUL	>512	0.12	0.06
Cefepime	0.25	0.12	0.06
Cefepime + CLA	0.25	0.06	0.06
Cefepime + TZB	0.25	0.06	0.06
Cefepime + SUL	0.25	0.06	0.06
Imipenem	0.5	0.06	0.06
Imipenem + CLA	0.5	0.06	0.06
Imipenem + TZB	0.5	0.06	0.06
Imipenem + SUL	0.5	0.06	0.06
Meropenem	0.25	<0.06	<0.06
Meropenem + CLA	0.25	<0.06	<0.06
Meropenem + TZB	0.25	<0.06	<0.06
Meropenem + SUL	0.25	<0.06	<0.06

^aCLA, clavulanic acid at a fixed concentration of 2 μg/ml; TZB, tazobactam at a fixed concentration of 4 μg/ml; SUL, sulbactam at a fixed concentration of 8 μg/ml.