TABLE 2.

Estimates of rates of mutation to ciprofloxacin and imipenem resistance for PAO1 and PAOΔmutS

Antibiotic and concn	Mutation rate (no. of mutants per cell per division)
	PAO1	PAOΔmutS
Ciprofloxacin
1 μg/ml	1.2 × 10−8	1.1 × 10−6
0.5 μg/ml	2.2 × 10−8	1.9 × 10−6
Imipenem
8 μg/ml	6.5 × 10−9	1.1 × 10−6
4 μg/ml	1.3 × 10−8	1.2 × 10−5