TABLE 2.

MICs for and antimicrobial susceptibilities of 25 B. anthracis strains

Anti- microbial	MIC (μg/ml)a			Categorical interpretation
	Range	50%	90%	No. of isolates			Staphylococcal breakpoint (μg/ml)b
				S	I	R	S	I	R
Cefaclor	0.125-0.75	0.38	1.65	25			≤8	16	≥32
Cefuroxime	6-48	21.33	32	1	19	5	≤8	16	≥32
Cephalexin	0.38-2	1.5	1.5	25			≤8	16	≥32
Ciprofloxacin	0.032-0.38	0.094	0.094	25			≤1	2	≥4
Doxycycline	0.094-0.38	0.23	0.34	25			≤4	8	≥16
Penicillin	<0.016-0.5	0.042	0.236	22		3	≤0.12		≥0.25
Tobramycin	0.25-1.5	0.75	0.97	25			≤4	8	≥16

^a50 and 90%, MIC₅₀ and MIC₉₀, respectively.

^bNCCLS standard M100-S12.