Table 1.

Characteristics of the 11 clinical isolates and two control strains used in this study

Isolate or strain	mec type	PVLa	Infection type	PSMb baseline	MIC (μg/ml)c
					TYG	CL	LZ
1	IV	+	Blood	Low	0.125	0.188	3
2	IV	+	Blood	Medium	0.125	0.25	3
3	IV	+	Blood	Low	0.125	0.188	2
4	IV	+	Blood	Medium	0.125	0.25	2
5	IV	+	Blood	Medium	0.125	0.188	2
6	IV	+	Pneumonia	Low	0.188	0.125	2
7	IV	+	Pneumonia	Medium	0.125	0.188	3
8	IV	+	Necrotizing pneumonia	High	0.125	0.25	3
9	II	−	Pneumonia	Very low	0.125	>256	3
10	II	−	Pneumonia	Very low	0.125	>256	1
11	II	−	Pneumonia	Very low	0.125	0.188	2
Control strains
USA300 (LAC)	IV	+	Wound	Medium	0.25	0.25	2
USA600	II	−	Blood	Low	0.125	>256	2

^aA plus or minus sign denotes the presence or absence, respectively, of the lukF/S gene, which encodes the Panton-Valentine leukocidin.

^bThe PSMα₃ production level at the baseline was arbitrarily defined as very low (<1 μg/ml), low (1 to 5 μg/ml), medium (6 to 15 μg/ml), or high (>15 μg/ml).

^cTYG, tigecycline; CL, clindamycin; LZ, linezolid. Resistance is defined as a MIC of >256 μg/ml (not tested for PSMα production at subinhibitory concentration).