Table 2.

Spontaneous resistance frequencies of PF for S. aureus.

Strains	Antimicrobial	Spontaneous resistance frequency (±SD)
		2× MIC	4× MIC
ATCC 43300	PF	2.63 × 10−9 (±2.63 × 10−9)	8.77 × 10−10 (±1.52 × 10−9)
	Rifampin	1.06 × 10−7 (±9.35 × 10−9)	2.10 × 10−8 (±5.25 × 10−9)
	Ciprofloxacin	6.63 × 10−7 (±2.39 × 10−8)	1.66 × 10−8 (±4.01 × 10−9)
ATCC 29213	PF	1.66 × 10−9 (±2.88 × 10−9)	4.16 × 10−10 (±7.21 × 10−10)
	Rifampin	1.08 × 10−8 (±5.02 × 10−9)	6.67 × 10−9 (±1.91 × 10−9)
	Ciprofloxacin	3.13 × 10−7 (±1.40 × 10−8)	3.75 × 10−9 (±3.30 × 10−9)