Table 1

Minimal inhibitory concentration (MIC) (μg/mL) and range of rifaximin and norfloxacin for susceptible and resistant bacteria

	Number of isolates	Rifaximin			Norfloxacin
Micro-organisms	Number of isolates	MIC₅₀, μg/mL	MIC₉₀, μg/mL	MIC range, μg/mL	MIC₅₀, μg/mL	MIC₉₀, μg/mL	MIC range, μg/mL
MS S. epidermidis	10	≤0.007	≤0.007	≤0.007–8	0.25	64	0.015–64
MR S. epidermidis	20	≤0.007	≤0.007	≤0.007–16	2	32	0.015–32
MS S. aureus	20	≤0.007	≤0.007	≤0.007	1	128	0.5–128
MR S. aureus	20	≤0.007	0.06	≤0.007–2	128	>128	32–>128
PS E. faecalis	20	2	4	0.25–4	4	64	2–>128
PR E. faecium	16	4	16	1–>128	>128	>128	16–>128
Escherichia coli susceptible	20	8	8	1–16	0.125	1	0.03–1
MDR E. coli	23	8	16	4–16	64	128	2–>128
MDR Kebsiella pneumoniae	27	32	64	16–128	32	128	0.06–>128
MDR Proteus mirabilis	5	4	4	0.06–4	8	64	0.05–64
MDR Citrobacter, Morganella and Enterobacter	5	16	32	0.03–32	0.25	32	0.125–32
MDR P. aeruginosa	13	16	16	8–16	16	128	0.125–128
MDR A. baumannii	14	1	4	0.25–4	>128	>128	128–>128

MDR, multidrug-resistant; MS, methicillin-susceptible; MR, methicillin-resistant; PS, penicillin-susceptible; PR, penicillin-resistant.