TABLE 1.

Induction of stringent stress response by mupirocin: impact on the resistance level and relative amounts of PBP 2A in auxiliary mutants^a

Mutation no.b	Strain or mutant	Inactivated gene	MIC of oxacillin (μg/ml)		Relative amt of PBP 2A (%)c
			None	With mupirocind	None	With mupirocind
	COL	None	>256	>256	100e	100
1	RUSA162	SACOL0181	32	>256	30	110
5	RUSA262	SACOL0830	1.5	128	10	90
6	RUSA235	murE (femF)	1	>256	20	95
8	SABS1	ptc1	0.38	>256	ND	ND
11	RUSA209	glnR (femC)	0.19	>256	10	100
12	RUSA164	tkt	16	>256	ND	ND
15	RUSA279	trpG	64	>256	ND	ND
16	BB308	femA	0.094	0.094	ND	ND
17	RUSA10	femB	0.032	0.064	0.5	5
19	RUSA239	lysA	0.25	>256	25	120
21	RUSA130	pbp2	48	>256	30	100
24	RUSA188	pepV	64	>256	ND	ND
31	RUSA315	glmM (femD)	0.094	>256	0.5	95

^aDetermination of MIC and amount of PBP 2A was performed three times independently, with similar results.

^bMutation numbers as shown in Table S1.

^cND, not determined.

^dMupirocin (0.03 μg/ml) was added to the growth medium as a reagent to induce the stringent stress response (11).

^eThe amount of PBP 2A in COL was set to 100% as a control.