Table 2. Mutation rate and sensitivity to DNA damage are unchanged in cells expressing the DNA damage response.

Genotype	mutants/cell/generation (95% CI)	MIC ciprofloxacin, µg/ml (+/− SD)
Wild type	4.7×10−9 (2.7–7.1×10−9)	0.18 (+/−0.03)
ΔaddA	1.5×10−8 (0.5–8.4×10−8)*	0.053 (+/−.01)
comB4IE	4.5×10−9 (1.6–5.4×10−9)**	0.17 (+/−0.03)

Mutation rate of sacB was determined by fluctuation analysis and p values were determined by student's T-test in comparison to wild type. *p = 0.07, **p = 1. MIC of ciprofloxacin was determined by E-test (Biodisk). SD = standard deviation.