TABLE 3.

β-Lactam MICs for K. oxytoca strains ATCC 13182^T, SC 10,436, SG266, and SG271

β-Lactam	MIC (μg/ml)
	ATCC 13182Ta	SC 10,436b	SG266	SG271
Amoxicillin	128	>1,024	64	16
+ 2 μg of clavulanate/ml	1	128	0.5	0.25
Ticarcillin	32	>1,024	64	16
+ 2 μg of clavulanate/ml	1	256	2	0.5
Piperacillin	2	512	2	1
+ 4 μg of tazobactam/ml	0.5	256	0.5	0.12
Cephalothin	2	64	2	2
Cefoxitin	0.5	1	1	0.5
Cefotaxime	≤0.06	2	≤0.06	≤0.06
Ceftazidime	0.12	1	≤0.06	≤0.06
Cefepime	≤0.06	2	≤0.06	≤0.06
Aztreonam	≤0.06	32	≤0.06	≤0.06
Imipenem	0.5	0.5	0.5	0.5

^aStrain ATCC 13182^T (14) harboring a bla_OXY-2 gene under the control of a wild type promoter.

^bStrain SC 10,436 (12) harboring a bla_OXY-2 gene under the control of a mutated promoter responsible for the β-lactamase overproduction.