TABLE 1.

In vitro potencies of oral beta-lactams in combination with QPX7728 at 4 μg/mL against isogenic strains of Klebsiella pneumoniae expressing cloned beta-lactamases^a

Strain	Beta-lactamase	MIC (μg/mL)
		Tebipenem	Tebipenem + QPX7728	Ceftibuten	Ceftibuten + QPX7728	Cefixime	Cefixime + QPX7728	Cefditoren	Cefditoren + QPX7728	Cefdinir	Cefdinir + QPX7728	Cefpodoxime	Cefpodoxime + QPX7728
KPM1116	None	≤0.06	≤0.06	≤0.06	≤0.06	≤0.06	≤0.06	0.25	≤0.06	0.125	≤0.06	≤0.06	≤0.06
KPM1113	KPC-2	0.5	≤0.06	0.5	≤0.06	2	≤0.06	>64	≤0.06	16	≤0.06	16	≤0.06
KPM1031	CTX-M-14	≤0.06	≤0.06	2	≤0.06	16	≤0.06	32	≤0.06	256	≤0.06	256	≤0.06
KPM1114	CTX-M-15	≤0.06	≤0.06	4	≤0.06	32	≤0.06	64	≤0.06	256	≤0.06	>256	≤0.06
KPM1115	SHV-12	≤0.06	≤0.06	2	≤0.06	16	≤0.06	32	≤0.06	4	≤0.06	16	≤0.06
KPM3258	SHV-5	≤0.06	≤0.06	2	≤0.06	16	≤0.06	64	≤0.06	8	≤0.06	64	≤0.06
KPM1112	TEM-10	≤0.06	≤0.06	0.25	≤0.06	4	≤0.06	16	≤0.06	0.5	≤0.06	8	≤0.06
KPM3736	PER-2	≤0.06	≤0.06	16	≤0.06	16	≤0.06	16	≤0.06	32	≤0.06	64	0.5 (8)
KPM3812	VEB-2	≤0.06	≤0.06	16	≤0.06	64	≤0.06	64	≤0.06	32	≤0.06	16	≤0.06
KPM1956	P99-like AmpC	≤0.06	≤0.06	64	≤0.06	128	≤0.06	64	≤0.06	64	≤0.06	32	≤0.06
KPM1030	DHA-1	≤0.06	≤0.06	16	≤0.06	32	≤0.06	4	≤0.06	16	≤0.06	16	≤0.06
KPM1045	CMY-2	≤0.06	≤0.06	32	≤0.06	>64	≤0.06	64	≤0.06	32	≤0.06	128	≤0.06
KPM3352	MIR-1	≤0.06	≤0.06	64	≤0.06	>64	≤0.06	64	≤0.06	64	≤0.06	>64	2 (32)
KPM1939	OXA-48	0.5	≤0.06	≤0.06	≤0.06	≤0.06	≤0.06	1	≤0.06	16	≤0.06	≤0.06	≤0.06
KPM1932	NDM-1	32	≤0.06	64	0.125	256	0.5 (8)	256	0.25 (4)	256	1 (16)	256	2 (32)
KPM1935	VIM-1	8	≤0.06	32	≤0.06	256	≤0.06	256	≤0.06	256	0.125	256	0.125
KPM1996	IMP-1	4	≤0.06	64	≤0.06	128	≤0.06	128	≤0.06	64	0.25	128	0.25 (4)

^aBold numbers in parentheses indicate MIC ratios between the beta-lactamase-producing strains and the vector-alone strain that are equal to or higher than 4. Data for ceftibuten, tebipenem, and cefpodoxime were presented earlier (14).