TABLE 3.

Antibiotic susceptibility profiles of K. pneumoniae isolates at two cell densities

Strain (enzyme[s])	Cell density (CFU/ml)	MIC (μg/ml)a
		Carbapenems			Cephalosporins				Monobactam: ATM	Penicillin with or without oxapenam
		MK-0826	MERc	IPM	CTRX	CAZ	CTX	CPM		AM	AM/CA	CA
CL 5188 (TEM-10, SHV-1)	1.5 × 106	0.12	0.06	0.25	32	>128	16	16	>128	>128	16/8	32
	1.5 × 107	1 [8]	1 [16]	1 [4]	>128 [>4]	>128	>128 [>8]	>128 [>8]	>128	>128	64/32 [4]	>256 [>8]
CL 5189 (TEM-10, SHV-1)	1.8 × 106	≤0.03	≤0.03	0.06	4	>128	1	2	64	>128	8/4	16
	1.8 × 107	0.25 [≥8]	0.25 [≥8]	0.25 [4]	128 [32]	>128	32 [32]	128 [64]	>128 [>2]	>128	16/8 [2]	32 [2]
CL 5128 (TEM-5)	1.1 × 106	0.12	≤0.03	0.06	8	64	4	2	16	>128	32/16	16
	1.1 × 107	1 [8]	0.12 [≥4]	0.5 [8]	64 [8]	64 [1]	>128 [>32]	128 [64]	>128 [>8]	>128	32/16 [1]	4 [0.25]
CL 5196 (TEM-10)	1.2 × 106	0.06	≤0.03	0.5	2	>128	1	4	128	>128	8/4	32
	1.2 × 107	0.5 [8]	1 [≥32]	1 [2]	>128 [>64]	>128	128 [128]	128 [32]	>128	>128	16/8 [2]	>256 [>8]
CL 5203 (unchar. ESBLb)	9.9 × 105	≤0.03	≤0.03	0.25	0.5	64	0.5	0.5	8	>128	8/4	64
	9.9 × 106	0.5 [≥16]	1 [≥32]	0.5 [2]	32 [64]	>128 [>2]	0.5 [1]	64 [128]	>128 [>16]	>128	16/8 [2]	>256 [>4]
CL 5212 (unchar. ESBLb)	9.6 × 105	0.12	0.06	0.5	>128	>128	>128	>128	>128	>128	16/8	>256
	9.6 × 106	0.5 [4]	0.5 [8]	0.5 [1]	>128	>128	>128	>128	>128	>128	32/16 [2]	>256

^aFold MIC increases at 10× inoculum are shown in brackets. Fold MIC changes were calculated based on serial twofold antibiotic dilutions prior to rounding off of MIC values. 

^bESBL presumed to be TEM-26 (see Table 1, footnote b). unchar., uncharacterized. 

^cAntibiotic abbreviations: MER, meropenem; IPM, imipenem; CTRX, ceftriaxone; CAZ, ceftazidime; CTX, cefotaxime; CPM, cefepime; ATM, aztreonam; AM, amoxicillin; AM/CA, amoxicillin-clavulanic acid, 2:1; CA, clavulanic acid.