TABLE 3.

Range of Etest MIC results for three quality control organisms

Strain	MICs ofa:
	Erythromycin		Rifampin		Chloramphenicol		Trimethoprim-sulfamethoxazole
	BGA	RL−C	BGA	RL−C	BGA	RL−C	BGA	RL−C
S. aureus ATCC 29213b	0.5–1.0 (1.0)	0.5–1.0 (1.0)	0.12–0.25 (0.12)	0.12–0.25 (0.12)	8	8–16 (8)	0.06–0.125 (0.125)	0.125 (0.125)
B. pertussis ATCC 9797	0.06–0.12 (0.125)	0.06–0.12 (0.12)	2.0–4.0 (2)	2.0–4.0 (2)	0.12–0.5 (0.5)	0.12–2.0 (1)	0.008–0.06 (0.06)	0.016–0.06 (0.06)
B. pertussis CDC-B100	>256	>256	2.0–8.0 (2)	2.0–8.0 (2)	0.5–1.0 (0.5)	1.0–2.0 (1)	0.008–0.12 (0.06)	0.004–0.12 (0.06)

^aResults are given in micrograms per milliliter. Modes are shown in parentheses. 

^bNCCLS quality control ranges for S. aureus ATCC 29213 are as follows: erythromycin, 0.25 to 1.0 μg/ml; rifampin, 0.004 to 0.015 μg/ml; chloramphenicol, 2 to 8 μg/ml; and trimethoprim-sulfamethoxazole, ≤0.5/9.5 μg/ml.