Table 1.

In vitro activity of MRX-8 and other comparator agents against 122 of Escherichia coli (mg/L).

Isolates	Antimicorbial agents	MIC (mg/liter)			R, %	S, %
		Range	50%	90%
polymyxin non-resistant and carbapenem-susceptible Escherichia coli (n = 58)	MRX-8	0.06-0.5	0.125	0.25	0	100
	Polymyxin B	0.125-1	0.25	0.5	0	100
	Colistin	0.125-1	0.25	0.5	0	100
	Amikacin	1->64	4	8	3.4	93.1
	Ceftriaxone	≤0.06->64	>64	>64	72.4	27.6
	Ceftazidime	0.125->64	8	>64	44.8	41.4
	Cefepime	≤0.06->64	16	>64	67.2	29.3
	Ceftazidime-avibactam	≤0.06->64	0.25	2	8.6	91.4
	Cefoperazone-sulbactam	0.25->64	8	64	17.2	69
	Meropenem	≤0.06-1	0.06	0.125	0	100
	Ciprofloxacin	≤0.06->64	16	>64	70.7	17.2
polymyxin non-resistant and carbapenem-resistant Escherichia coli (n = 46)	MRX-8	0.06-0.5	0.06	0.125	0	100
	Polymyxin B	0.125-1	0.25	0.25	0	100
	Colistin	0.125-1	0.125	0.25	0	100
	Amikacin	1->64	8	>64	39.1	56.5
	Ceftriaxone	>64->64	>64	>64	100	0
	Ceftazidime	32->64	>64	>64	100	0
	Cefepime	>64->64	>64	>64	100	0
	Ceftazidime-avibactam	≤0.06->64	>64	>64	84.8	15.2
	Cefoperazone-sulbactam	32->64	>64	>64	97.8	0
	Meropenem	4->16	>16	>16	100	0
	Ciprofloxacin	1->64	>64	>64	100	0
Polymyxin-resistant Escherichia coli (n = 18)	MRX-8	2->32	4	>32	94.4	5.6
	Polymyxin B	4->32	4	>32	100	0
	Colistin	4->8	4	>8	100	0
	Amikacin	1->64	2	>64	27.8	66.7
	Ceftriaxone	≤0.06->64	>64	>64	77.8	22.2
	Ceftazidime	0.125->64	64	>64	66.7	33.3
	Cefepime	≤0.06->64	64	>64	66.7	22.2
	Ceftazidime-avibactam	≤0.06->64	0.5	>64	22.2	77.8
	Cefoperazone-sulbactam	0.5->64	32	>64	44.4	38.9
	Meropenem	≤0.06->16	0.06	>16	22.2	77.8
	Ciprofloxacin	0.5->64	32	>64	88.9	5.6

R, resistant; S, susceptible. All the intermediate data were not showed in table.