TABLE 2.

In vitro activity of ceftazidime-avibactam against Gram-negative isolates from patients enrolled in the phase 3 clinical trial by ESBL phenotype (all randomized patients)^a

Baseline pathogen	ESBL statusb	No. of pathogens tested	MIC datac
			Range (μg/ml)	MIC50 (μg/ml)	MIC90 (μg/ml)	%Sd
Enterobacteriaceae
Escherichia coli	ESBL phenotype positive	108	≤0.008–2	0.12	0.5	100
	ESBL phenotype negative	31	0.06–8	0.25	8	100
Klebsiella pneumoniae	ESBL phenotype positive	106	0.12–2	0.5	1	100
	ESBL phenotype negative	25	0.06–>256	0.5	4	92.0
Proteus mirabilis	ESBL phenotype positive	2	0.06–0.5	NAe	NA	100
	ESBL phenotype negative	7	0.03–2	NA	NA	100

^aA patient could have more than one pathogen. Multiple isolates of the same species from the same patient are counted only once using the isolate with the highest MIC to the study drug received. For bacteremic patients, multiple isolates of the same species from the same patient are counted only once using the isolate with the highest MIC to the study drug received across the culture source (urine or blood).

^bGenetic identification of β-lactamases was provided as previously described (JMI Laboratories, Inc., North Liberty, IA) (9).

^cThe total number of patients in the treatment group was 333.

^d%S, percent susceptible.

^eNA, not applicable. MIC₅₀ and MIC₉₀ values were not calculated for pathogens with <10 patients.