Defining the potency of amikacin against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii derived from Chinese hospitals using CLSI and inhalation-based breakpoints

Figures & data

Table 1 MIC₅₀, MIC₉₀, range, and percent susceptibility for amikacin and comparators against Escherichia coli and Klebsiella pneumoniae isolates

Isolates	Antimicrobial	MIC50(mg/L)	MIC90(mg/L)	Range(mg/L)	%S
E. coli, all isolates	Amikacin	2	4	1–>256	94.7 (95.4)^a
(n = 188)	Cefoxitin	8	64	2->256	62.9
	Cefepime	2	32	≤0.016–>256	53.6
	Ceftazidime	2	64	0.064–>256	64.9
	Cefotaxime	16	256	0.032–>256	32.5
	Ceftriaxone	32	256	0.032–>256	32.5
	Ciprofloxacin	16	>64	≤0.0l6–>64	34.4
	Ertapenem	0.032	0.25	≤0.0l6–>64	96.0
	Imipenem	0.125	0.25	≤0.016–16	98.0
	Levofloxacin	8	>64	≤0.0l6–>64	37.1
	Meropenem	≤0.016	0.032	≤0.016–>32	98.0
	Minocycline	2	16	^0.^5^–l^200	72.8
	Piperacillin/tazobactam	2	8	0.5–>256	92.1
	Polymyxin B	0.125	0.25	0.064–8	NA^b
	Tigecycline	0.25	0.5	0.125–2	I00^c
E. coli, ESBL producing	Amikacin	2	8	1–>256	93.0 (94.2)^a
001 1(n	Cefoxitin	8	32	2–>256	60.5
	Cefepime	8	32	0.032–>256	25.6
	Ceftazidime	4	64	0.125–>256	54.7
	Cefotaxime	64	256	2–>256	0.0
	Ceftriaxone	64	256	4–>256	0.0
	Ciprofloxacin	32	>64	≤0.0l6–>64	20.9
	Ertapenem	0.032	0.25	≤0.016–2	98.8
	Imipenem	0.125	0.25	≤0.016–0.5	I00
	Levofloxacin	16	>64	≤0.0l6–>64	25.6
	Meropenem	≤0.016	0.032	≤0.016–0.125	I00
	Minocycline	2	16	0.5–l28	68.6
	Piperacillin/tazobactam	2	4	0.5–64	96.5
	Polymyxin B	0.125	0.25	0.064–8	NA^b
	Tigecycline	0.25	0.5	0.l25–2	I00^c
K. pneumoniae,	Amikacin	1	>256	0.5–>256	83.7 (83.7)^a
all isolates	Cefoxitin	4	>256	1–>256	65.9
001 1(n	Cefepime	0.25	64	≤0.0l6–>256	6l.2
	Ceftazidime	0.5	128	0.032–>256	66.7
	Cefotaxime	0.5	256	≤0.0l6–>256	52.7
	Ceftriaxone	0.5	256	≤0.0l6–>256	5l.2
	Ciprofloxacin	0.25	>64	≤0.0l6–>64	64.3
	Ertapenem	≤0.016	32	≤0.0l6–>32	80.6
	Imipenem	0.25	16	≤0.0l6–>32	79.8
	Levofloxacin	0.25	32	≤0.0l6–>64	69.0
	Meropenem	0.032	32	≤0.0l6–>32	82.2
	Minocycline	4	32	0.5–256	54.3
	Piperacillin/tazobactam	4	>256	≤0.0l6–>256	76.7
	Polymyxin B	0.25	0.5	0.064–4	NA^b
	Tigecycline	1	2	≤0.0l6–8	96.l^c
K. pneumoniae, ESBL	Amikacin	1	>256	0.5–>256	71.1 (7I.I)^a
producing	Cefoxitin	8	256	2–>256	60.0
(n = 45)	Cefepime	8	32	l–64	20.0
	Ceftazidime	16	64	0.25–>256	37.8
	Cefotaxime	64	256	4–>256	0.0
	Ceftriaxone	64	256	8–>256	0.0
	Ciprofloxacin	16	>64	0.032–>64	35.6
	Ertapenem	0.125	32	≤0.0l6–>32	77.8
	Imipenem	0.25	16	≤0.0l6–>32	77.8
	Levofloxacin	4	64	0.032–>64	44.4
	Meropenem	0.032	8	≤0.016–>32	80.0
	Minocycline	8	64	0.5–128	26.7
	Piperacillin/tazobactam	4	>256	0.5–>256	71.1
	Polymyxin B	0.25	0.25	0.064–4	NA^b
	Tigecycline	1	2	0.125–8	95.6^c

Notes: ^aAmikacin percent susceptibility calculated using the CLSI breakpoint of ≤ 16 mg/L (PD threshold concentration: ≤ 256 mg/L).

b Polymyxin B susceptibility breakpoints are not established by CLSI or the FDA.

c Tigecycline percent susceptibility calculated using the FDA breakpoint of ≤ 2 mg/L.

Abbreviations: MIC, minimum inhibitory concentration; %S, percentage susceptibility; ESBL, extended-spectrum beta-lactamase; CLSI, Clinical and Laboratory Standards Institute; FDA, US Food and Drug Administration; PD, pharmacodynamic.

Table 2 MIC₅₀, MIC₉₀, range, and percent susceptibility for amikacin and comparators against Pseudomonas aeruginosa and Acinetobacter baumannii

Isolates	Antimicrobial	MIC50(mg/L)	MIC90(mg/L)	Range(mg/L)	%S
P. aeruginosa, all isolates	Amikacin	2	8	≤0.016–>256	91.1 (92.0)^a
(n = 112)	Cefepime	2	16	≤0.016–256	80.4
	Ceftazidime	2	64	≤0.016–>256	81.3
	Ciprofloxacin	0.125	4	0.032–>64	83.9
	Imipenem	2	32	≤0.016–>32	59.8
	Levofloxacin	0.5	8	≤0.0l6–>64	81.3
	Meropenem	0.5	16	≤0.016–>32	68.8
	Piperacillin/tazobactam	4	128	≤0.016–>256	79.5
	Polymyxin B	0.5	1	0.032–2	100
P. aeruginosa, CRPA	Amikacin	2	>256	0.5–>256	80.9 (83.0)^a
(n = 47)	Cefepime	8	64	1–256	59.6
	Ceftazidime	4	256	0.5–>256	66.0
	Ciprofloxacin	0.5	32	0.064–>64	68.1
	Imipenem	16	>32	2–>32	4.3
	Levofloxacin	2	32	0.125–>64	63.8
	Meropenem	8	>32	0.25–>32	25.5
	Piperacillin/tazobactam	16	256	0.25–>256	59.6
	Polymyxin B	0.5	1	0.25–2	100
A. baumannii, all isolates	Amikacin	>256	>256	1–>256	30.5 (3l.3)^a
(n = 131)	Cefepime	64	128	0.032–256	16.0
	Ceftazidime	128	>256	0.125–>256	18.3
	Ciprofloxacin	64	>64	≤0.0l6–>64	18.3
	Imipenem	>32	>32	0.25–>32	15.3
	Levofloxacin	8	16	0.032–32	19.1
	Meropenem	32	>32	0.032–>32	15.3
	Minocycline	4	16	0.032–256	61.8
	Piperacillin/tazobactam	>256	>256	≤0.016–>256	14.5
	Polymyxin B	0.25	0.5	0.125–>32	99.2
	Tigecycline	2	4	0.064–32	NA^b
A. baumannii, CRAB	Amikacin	>256	>256	2–>256	18.0 (I8.0)^a
(n = 111)	Cefepime	64	128	2–256	0.9
	Ceftazidime	128	>256	4–>256	3.6
	Ciprofloxacin	64	>64	0.064–>64	3.6
	Imipenem	>32	>32	8–>32	0
	Levofloxacin	8	16	0.064–32	4.5
	Meropenem	32	>32	8–>32	0
	Minocycline	4	16	0.064–256	55.9
	Piperacillin/tazobactam	>256	>256	64–>256	0
	Polymyxin B	0.25	0.5	0.125–>32	99.1
	Tigecycline	2	4	0.125–32	NA^b

Notes: ^aAmikacin percent susceptibility calculated using the CLSI breakpoint of ≤ 16 mg/L (PD threshold concentration: ≤ 256 mg/L).

b Tigecycline susceptibility breakpoints are not established by CLSI or the FDA.

Abbreviations: MIC, minimum inhibitory concentration; %S, percentage susceptibility; CRPA, carbapenem-resistant P. aeruginosa; CRAB, carbapenem-resistant A. baumannii; CLSI, Clinical and Laboratory Standards Institute; FDA, US Food and Drug Administration; PD, pharmacodynamic.