TABLE 2.

MIC distribution of sitafloxacin for 194 clinical, M. abscessus isolates.

M. abscessus	No. of isolates	Number of isolates exhibiting the MIC (mg/L) of sitafloxacin indicated						MIC50 (mg/L)a	MIC90 (mg/L)a
		0.25	0.5	1	2	4	8
subsp. abscessusb	148	11	55	63	15	3	1	1	2
subsp. Massiliense	46	1	10	18	16	1	0	1	2

^aMIC₅₀ and MIC₉₀, the sitafloxacin concentration at which 50 and 90% of the clinical isolates tested, respectively, were inhibited. ^bM. abscessus subsp. abscessus was significantly more sensitive than subsp. massiliense to sitafloxacin treatment, P < 0.001.