TABLE 1.

Adaptive resistance to MB-1 by P. aeruginosa strain JJ4-36 wild-type and isogenic pyoverdine biosynthesis and secretion mutants

CDMHB plate addition	Highest MB-1 concn (μg/ml) with growth in:
	WT JJ4-36	JJ4-36 ΔpvdA	JJ4-36 ΔRTQ
Unsupplemented	32	<0.25	0.25
1% WT CMa	NTb	16	4
1% ΔpvdA CM	NT	0.25	0.25

^aCM, conditioned medium (defined as cell-free spent medium harvested from wild-type [WT] or pyoverdine-deficient [ΔpvdA] P. aeruginosa strain JJ4-36 grown overnight in CDMHB at 37°C).

^bNT, not tested.