TABLE 2.

In vitro activities of fluoroquinolones against 187 Korean C. difficile isolates according to toxigenic status

Toxin status (no. of isolates tested)	Antimicrobial agent	MIC (μg/ml)
		Range	MIC50	MIC90
A+ B+ (115)	Norfloxacin	16-256	64	128
	Ciprofloxacin	4-128	16	32
	Ofloxacin	8-256	64	128
	Levofloxacin	2-128	32	64
	Gatifloxacin	1-32	8	8
	Moxifloxacin	1-16	8	8
A− B+ (31)	Norfloxacin	32-128	64	128
	Ciprofloxacin	8-64	32	32
	Ofloxacin	8-256	128	256
	Levofloxacin	4-128	64	128
	Gatifloxacin	1-32	32	32
	Moxifloxacin	1-32	32	32
A− B− (41)	Norfloxacin	32-128	32	64
	Ciprofloxacin	4-32	8	8
	Ofloxacin	8-256	8	8
	Levofloxacin	4-128	4	4
	Gatifloxacin	1-32	1	2
	Moxifloxacin	1-16	1	2