Table 1. MICs for various β-lactams with B. thailandensis strains.

Strain	MIC (µg/ml)a
	AMX/CLA	CTXM	CRX	CEF
Wild type
E264 (penA-WT)	6	6	16	18
Mutant
E264 (penA-TR10)	3	1.5	1	8
E264 (penA-TR11)	3	1.625	0.5	12
penA -null mutant strains
E264 (ΔpenA-WT)	1.5	1	0.5	3
E264 (ΔpenA-TR10)	2	0.75	0.25	6
E264 (ΔpenA-TR11)	2	1	0.38	6
penA -null mutants complemented by penA alleles carried by pRK415K
E264 (ΔpenA-WT, complemented)	48	>32	>32	64
E264 (ΔpenA-TR10, complemented)	2.5	3	2	24
E264 (ΔpenA-TR11, complemented)	3	4.5	4	40

^aMICs were measured by the E-test.

Abbreviations: AMX, amoxicillin; CLA, clavulanic acid; CTXM, cefotaxime; CRX, ceftriaxone; CEF, cefepime.