TABLE 3.

Bacterial strains and plasmids used in this study

Bacterial strain or plasmid	Descriptiona	Source or reference
Bacterial strains
S. epidermidis RP62A	Standard strain of S. epidermidis, biofilm positive	ATCC
S. epidermidis 1457	Clinical strain, biofilm positive	21
ΔvraSR mutant	vraSR deletion mutant derived from SE1457	This study
ΔvraSR(pRAB11-vraSR) mutant	ΔvraSR mutant complemented with plasmid pRAB11-vraSR	This study
ΔvraSR(pRAB11) mutant	ΔvraSR mutant introduced with plasmid pRAB11	This study
ΔicaC mutant	icaC gene deletion mutant derived from SE1457	22
ΔatlE mutant	atlE gene deletion mutant derived from SE1457	27
S. aureus 4220	Restriction negative, modification positive	Gao Fu, University of Hong Kong
E. coli DH5α	supE44ΔlacU169 (80dlacZΔM15) hsdR17 recA1 endA1 gyrA96 thi-1 relA1	Invitrogen
E. coli BL21(DE3)	F− ompT hsdSB (rB− mB−) gal dcm (DE3)	Invitrogen
Plasmids
pET28a	E. coli expression plasmid; Kmr	Novagen
pET28a-vraR	pET28a harboring the vraR gene, used for VraR expression	This study
pKOR1	Temp-sensitive E. coli (Ampr)-Staphylococcus (Cmr) shuttle vector	Li Ming, Fudan University
pKOR1-ΔvraSR	Recombinant plasmid	This study
pRAB11	Shuttle vector; Ampr Cmr	41
pRAB11-vraSR	The vraSR genes were cloned into pRAB11	This study

^aKm^r, kanamycin resistance; Amp^r, ampicillin resistance; Cm^r, chloramphenicol resistance.