Table 2.

MIC₅₀, MIC₉₀ and MIC range (mg/L) of, and antimicrobial susceptibility and resistance to, ceftazidime/avibactam and comparator agents for Enterobacterales resistance phenotypes collected in Latin America as part of the INFORM study^a, 2015–17

Phenotype/antimicrobial	MIC50 (mg/L)	MIC90 (mg/L)	MIC range (mg/L)	S (%)	R (%)
ESBL positive (N = 1860)
ceftazidime/avibactam	0.25	1	≤0.015 to ≥256	98.2	1.8
ceftazidime	32	≥256	0.25 to ≥256	3.4	86.3
cefepime	≥32	≥32	≤0.12 to ≥32	2.6	91.1
amoxicillin/clavulanate	16	≥64	≤0.12 to ≥64	17.0	83.0
piperacillin/tazobactam	16	≥256	≤0.25 to ≥256	49.2	39.5
aztreonam	64	≥256	0.12 to ≥256	0.5	94.2
imipenem	0.25	4	≤0.03 to ≥16	88.7	8.4
meropenem	0.06	4	0.008 to ≥16	89.8	7.3
colistin	0.25	1	≤0.06 to ≥16	94.5	5.5
amikacin	4	16	≤0.25 to ≥64	83.1	9.0
levofloxacin	≥16	≥16	0.03 to ≥16	15.4	76.1
tigecycline	0.5	1	≤0.015 to ≥16	—	—
CBPM positive (N = 366)
ceftazidime/avibactam	1	64	≤0.015 to ≥256	86.9	13.1
ceftazidime	64	≥256	0.5 to ≥256	1.6	92.1
cefepime	≥32	≥32	≤0.12 to ≥32	4.1	86.3
amoxicillin/clavulanate	≥64	≥64	16 to ≥64	0.0	100
piperacillin/tazobactam	≥256	≥256	8 to ≥256	0.3	99.2
aztreonam	≥256	≥256	≤0.015 to ≥256	4.6	93.4
imipenem	≥16	≥16	0.25 to ≥16	5.2	80.9
meropenem	≥16	≥16	0.12 to ≥16	12.0	66.7
colistin	0.5	≥16	0.12 to ≥16	76.8	23.2
amikacin	4	≥64	≤0.25 to ≥64	60.9	26.5
levofloxacin	≥16	≥16	0.03 to ≥16	20.2	73.8
tigecycline	0.5	2	0.12 to 8	—	—
CBPM negative (N = 1840)
ceftazidime/avibactam	0.25	1	≤0.015 to ≥256	99.9	0.1
ceftazidime	32	128	0.12 to ≥256	5.2	81.8
cefepime	≥32	≥32	≤0.12 to ≥32	8.0	83.4
amoxicillin/clavulanate	16	≥64	≤0.12 to ≥64	18.3	81.7
piperacillin/tazobactam	8	≥256	≤0.25 to ≥256	53.7	34.7
aztreonam	32	≥256	≤0.015 to ≥256	2.9	89.8
imipenem	0.25	0.5	≤0.03 to ≥16	97.2	0.4
meropenem	0.06	0.12	0.008 to ≥16	98.3	0.4
colistin	0.25	1	≤0.06 to ≥16	95.8	4.2
amikacin	4	16	≤0.25 to ≥64	86.8	6.5
levofloxacin	≥16	≥16	0.03 to ≥16	19.2	72
tigecycline	0.25	1	≤0.015 to ≥16	—	—
MBL positive (N = 49)
ceftazidime/avibactam	≥256	≥256	8 to ≥256	2.0	98.0
ceftazidime	≥256	≥256	16 to ≥256	0.0	100
cefepime	≥32	≥32	1 to ≥32	2.0	95.9
amoxicillin/clavulanate	≥64	≥64	32 to ≥64	0.0	100
piperacillin/tazobactam	≥256	≥256	8 to ≥256	2.0	98.0
aztreonam	64	≥256	≤0.015 to ≥256	30.6	63.3
imipenem	≥16	≥16	2 to ≥16	4.1	77.6
meropenem	≥16	≥16	0.25 to ≥16	10.2	63.3
colistin	0.5	≥16	0.12 to ≥16	79.6	20.4
amikacin	16	≥64	1 to ≥64	49.0	38.8
levofloxacin	8	≥16	0.03 to ≥16	30.6	63.3
tigecycline	1	4	0.12 to 4	—	—
MBL negative (N = 2157)
ceftazidime/avibactam	0.25	1	≤0.015 to ≥256	99.9	0.1
ceftazidime	32	≥256	0.12 to ≥256	4.7	83.1
cefepime	≥32	≥32	≤0.12 to ≥32	7.5	83.6
amoxicillin/clavulanate	16	≥64	≤0.12 to ≥64	15.6	84.4
piperacillin/tazobactam	16	≥256	≤0.25 to ≥256	45.8	44.2
aztreonam	64	≥256	≤0.015 to ≥256	2.5	91.0
imipenem	0.25	8	≤0.03 to ≥16	83.7	12.3
meropenem	0.06	≥16	0.008 to ≥16	85.7	10.2
colistin	0.25	1	≤0.06 to ≥16	93.0	7.0
amikacin	4	16	≤0.25 to ≥64	83.3	9.1
levofloxacin	≥16	≥16	0.03 to ≥16	19.1	72.5
tigecycline	0.5	1	≤0.015 to ≥16	—	—

A dash indicates that breakpoints were unavailable for calculation of percentage susceptibility or resistance. CBPM, carbapenemase; R, resistant; S, susceptible.

^aINFORM was succeeded by ATLAS in 2018.