TABLE 5.

β-Lactam susceptibility of β-lactamase-deficient and MDR strains of S. maltophilia

Antibiotic	MIC (μg/ml) for:
	K1199 (parent)	K1385 (MDR)	K1445 (ULA-511 ΔL1)	K1446 (K1385 ΔL1)	K1447 (ULA-511 ΔL2)	K1448 (K1385 ΔL2)	K1449 (ULA-511 ΔL1 ΔL2)	K1450 (K1385 ΔL1 ΔL2)
Imipenem	512	512	4	4	512	512	0.25	0.5
Meropenem	1,024	512	1	2	512	512	0.25	0.5
Panipenem	>1,024	>1,024	64	64	>1,024	>1,024	4	8
R-83201	512	256	1	1	512	512	0.25	0.25
Penicillin G	>1,024	>1,024	1,024	512	>1,024	>1,024	1	1
Ampicillin	>1,024	>1,024	1,024	1,024	>1,024	>1,024	0.25	0.25
Unasyn	1,024	512	64	64	1,024	512	1	1
Amoxicillin	>1,024	>1,024	1024	512	>1,024	1,024	0.5	0.25
Cloxacillin	>1,024	>1,024	>1,024	>1,024	>1,024	>1,024	256	512
Carbenicillin	>1,024	>1,024	1,024	1,024	512	256	2	2
Piperacillin	>1,024	>1,024	512	256	>1,024	>1,024	8	32
Ticarcillin	>1,024	>1,024	1,024	1,024	256	128–256	2	2
Cefsulodin	>1,024	>1,024	>1,024	>1,024	4	4	4	4
Cefotaxime	512	256	256	128–256	128	128	2	2
Cefoperazone	>1,024	256	512	256	256	256	4	8
Ceftriaxone	512	512	256	256	256	256	2	2
Ceftazidime	256	256	128	128	256	256	2	2
Cefepime	128	64	128	64	8	8	1	8
Cefpirome	512	256	256	256	64	64	2	8
Aztreonam	>1,024	>1,024	>1,024	>1,024	4	4	2	8
Pirazmonam	8	1	4	2	1	0.5	1	0.5
Ciprofloxacina	4	32	4	32	4	32	4	32

^aIncluded to show that resistance to non-β-lactams was not affected by loss of the β-lactamases.