TABLE 2.

The PAO1 ΔrelA spoT mutant was more susceptible to antibiotics than its parent strain^a

Strain	MIC (μg/ml)
	Ciprofloxacin			Tobramycin			Imipenem			Ceftazidime
	LB	BM2 + CAA	BM2 − CAA	LB	BM2 + CAA	BM2 − CAA	LB	BM2 + CAA	BM2 − CAA	LB	BM2 + CAA	BM2 − CAA
PAO1	0.64	0.64	1.28	0.64	1.28	1.28	10.24	2.56	0.64	1.28	0.64	0.64
PAO1 ΔrelA spoT	0.32	0.32	0.32	0.32	0.64	0.64	5.12	1.28	0.32	0.64	0.32	0.32

^aThe MICs of ciprofloxacin, tobramycin, imipenem, and ceftazidime for which we observed 100% inhibition of planktonic growth were determined for Pseudomonas aeruginosa PAO1 and its (p)ppGpp mutant, PAO1 ΔrelA spoT. The media used were rich medium (LB), BM2 glucose minimal medium with 0.5% Casamino Acids (BM2 + CAA), and BM2 glucose minimal medium without additional CAA (BM2 − CAA).