Table 1.

Strains and plasmids used in this study

Strain or plasmid	Relevant characteristic(s)		Source or reference
E. faecium
E1162	Clinical isolate (bloodstream infection), isolated in France, 1996		[23]
ΔgltK	Markerless deletion mutant of gltK gene of E1162		This study
ΔgspA	Markerless deletion mutant of gspA gene of E1162		This study
ΔgltK+gltK	Complementation strain of ΔgltK; ΔgltK harboring pEF25-gltK		This study
ΔgspA+gspA	Complementation strain of ΔgspA; ΔgspA harboring pEF25-gspA		This study
E. coli strains
DH5α	E. coli host strain for routine cloning		Invitrogen
EC1000	MC1000 glgB::repA; host strain for pWS3 derived vectors		[24]
Plasmids
pWS3	Gram-positive thermosensitive origin of replication; Spcr		[29]
pDEL3a	pWS3 carrying the 5′ and 3′ flanking regions of gene gltK for mutant construction		This study
pDEL4a	pWS3 carrying the 5′ and 3′ flanking regions of gspA gene cluster for mutant construction		This study
pDEL3b	pDEL3a with a Genr cassette which was flanked by lox66- and lox71-sites cloned between the 5′ and 3′ flanking regions		This study
pDEL4b	pDEL4a with a Genr cassette which was flanked by lox66- and lox71-sites cloned between the 5′ and 3′ flanking regions		This study
pWS3-Cre	pWS3 derivative expressing Cre in E. faecium		[22]
pEF25	Shuttle plasmid pAT18 with spectinomycin resistance cassette cloned in the EcoRI site; Spcr Eryr		[30]
pEF25-gltK	Complementation plasmid for ΔgltK; pEF25 carrying gltK		This study
pEF25-gspA	Complementation plasmid for ΔgspA; pEF25 carrying gspA		This study