TABLE 2.

Activity of ceftolozane-tazobactam and comparator antimicrobial agents against H. influenzae isolates collected from medical centers in the United States and Europe, 2011 to 2018

Antimicrobial agent, by location	MIC (mg/liter)			Susceptibility (%) according toa :
				CLSI		EUCAST
	MIC50	MIC90	Range	S	R	S	R
All isolates (n = 900)
Ceftolozane-tazobactam	0.12	0.25	≤0.015 to 2	99.0b
Amoxicillin-clavulanic acid	≤1	2	≤1 to >8	99.7	0.3	97.7	2.3
Azithromycin	1	2	≤0.12 to >4	99.0		99.0c
Ceftazidime	0.06	0.12	≤0.015 to 1	100.0
Ceftriaxone	≤0.06	≤0.06	≤0.06 to 0.12	100.0		100.0	0.0
Ciprofloxacin	≤0.03	≤0.03	≤0.03 to >1	99.7		99.0	1.0
Levofloxacin	≤0.12	≤0.12	≤0.12 to >2	99.7
Meropenem	≤0.06	0.12	≤0.06 to 0.5	100.0		100.0d	0.0
Piperacillin-tazobactam	≤0.5	≤0.5	≤0.5 to ≤0.5	100.0	0.0
Tigecycline	0.12	0.25	0.06 to 1	90.6b
United States (n = 408)
Ceftolozane-tazobactam	0.12	0.25	≤0.015 to 2	99.0b
Amoxicillin-clavulanic acid	≤1	2	≤1 to >8	99.5	0.5	97.8	2.2
Azithromycin	1	2	≤0.03 to >4	99.3		99.3c
Ceftazidime	0.06	0.12	≤0.015 to 1	100.0
Ceftriaxone	≤0.06	≤0.06	≤0.06 to 0.12	100.0		100.0	0.0
Ciprofloxacin	≤0.03	≤0.03	≤0.03 to >1	99.8		99.0	1.0
Levofloxacin	≤0.12	≤0.12	≤0.12 to >2	99.8
Meropenem	≤0.06	0.12	≤0.06 to 0.25	100.0		100.0d	0.0
Piperacillin-tazobactam	≤0.5	≤0.5	≤0.5 to ≤0.5	100.0	0.0
Tigecycline	0.25	0.5	0.06 to 1	89.2b
Europe (n = 492)
Ceftolozane-tazobactam	0.12	0.25	≤0.015 to 1	99.0b
Amoxicillin-clavulanic acid	≤1	2	≤1 to 8	99.8	0.2	97.6	2.4
Azithromycin	1	2	≤0.12 to >4	98.8		98.8c
Ceftazidime	0.06	0.12	≤0.015 to 0.5	100.0
Ceftriaxone	≤0.06	≤0.06	≤0.06 to 0.12	100.0		100.0	0.0
Ciprofloxacin	≤0.03	≤0.03	≤0.03 to >1	99.6		99.0	1.0
Levofloxacin	≤0.12	≤0.12	≤0.12 to >2	99.6
Meropenem	≤0.06	0.12	≤0.06 to 0.5	100.0		100.0d	0.0
Piperacillin-tazobactam	≤0.5	≤0.5	≤0.5 to ≤0.5	100.0	0.0
Tigecycline	0.12	0.25	0.06 to 1	91.7b

^aCriteria as published by CLSI (16) and EUCAST (17). S, susceptible; R, resistant.

^bCriteria as published by FDA.

^cPercentage of wild type based on epidemiological cutoff values (17).

^dUsing nonmeningitis breakpoints.