TABLE 3.

Comparative susceptibilities to six fluoroquinolones and distribution of MICs among isolates^a

MIC (mg/liter)	% of strains or relative MICb
	Moxifloxacin				Gatifloxacin				Sitafloxacin				Ofloxacin				Levofloxacin				Sparfloxacin
	C	S	R−	R+	C	S	R−	R+	C	S	R−	R+	C	S	R−	R+	C	S	R−	R+	C	S	R−	R+
≤0.125		16	17			24	13			33	39							16			100	83	26
0.25	100	61	43		100	61	65		100	55	26		100	31			100	60	4			13	61	3
0.5		16	30			12	13			10	26	22		40				22	52			4	9	19
1		6	9	31		1	4	16		1	9	34		29				2	35	3				9
2		1		53			4	44				25			83	3			9	22			4	28
4				13		1		41				16			13	19				25				22
8				3								3			4	28				31
16																38				19				19
>16																13
MIC50	1	1	1	8	1	1	1	8	1	1	1	4	1	2	8	32	1	1	2	16	1	1	2	16
MIC90	1	2	2	16	1	2	2	16	1	2	2	16	1	4	16	>64	1	2	4	16	1	2	4	128

^aThere were four categories of M tuberculosis strains: C, the two ATCC control strains; S, 83 ofloxacin-susceptible strains (ofloxacin MIC < 2 mg/liter); R−, 23 ofloxacin-resistant isolates without gyrA mutations (ofloxacin MIC ≥ 2mg/liter); and R+, 32 ofloxacin-resistant isolates with gyrA mutations (ofloxacin MIC ≥ 2mg/liter).

^bSee Table 2, footnote a.