. 2011 May;55(5):1906–1911. doi: 10.1128/AAC.01645-10

Table 3.

Activities of antipseudomonal agents against P. aeruginosa bloodstream isolates with diverse resistance mechanisms

Antibiotic^a	All isolates (n = 190)			Isolates overexpressing ampC (n = 45)^b			Isolates overexpressing mexB (n = 24)			Isolates overexpressing mexY (n = 25)
Antibiotic^a	% S	MIC₅₀	MIC₉₀	% S	MIC₅₀	MIC₉₀	% S	MIC₅₀	MIC₉₀	% S	MIC₅₀	MIC₉₀
CAZ	76.3	4	32	17.8	32	128	58.7	8	64	68.0	8	32
FEP	61.6	8	32	17.8	32	64	25.0	16	32	16.0	16	32
ATM	67.4	8	32	22.2	16	64	33.3	16	32	40.0	16	16
PIP	80.5	8	128	28.9	128	128	79.2	32	128	68.0	16	128
PIP-Tz	86.3	8	128	44.4	128	256	79.2	16	256	80.0	16	128
IMP	67.9	2	32	37.8	16	32	41.7	8	32	32.0	16	32
MER	77.4	1	16	44.4	8	16	41.7	8	32	44.0	8	16
CIP	71.6	0.25	32	40.0	32	32	45.8	2	32	24.0	32	32
LEV	68.4	1	32	35.6	32	32	33.3	8	32	16.0	32	32
GEN	78.9	2	64	46.7	32	64	66.7	2	64	40.0	32	64
TOB	81.6	0.5	64	51.1	4	64	66.7	1	64	48.0	8	64
AMK	98.4	4	8	100	4	8	100	4	8	100	4	16
COL	96.8	0.5	1	93.3	0.5	1	95.8	0.5	1	100	0.5	1

CAZ, ceftazidime; FEP, cefepime; ATM, aztreonam; PIP, piperacillin; PIP-Tz, piperacillin-tazobactam; IMP, imipenem; MER, meropenem; CIP, ciprofloxacin; LEV, levofloxacin; GEN, gentamicin; TOB, tobramycin; AMK, amikacin; COL, colistin.

One of the isolates showing ampC overexpression additionally produced the MBL VIM-2 and was therefore excluded from this analysis.