TABLE 1.

Bacterial strains and plasmids used in this study^a

Strain or plasmid	Relevant genotype or phenotype	Comment(s)	Reference or sources
Bacterial strains
E. faecalis
FA2-2	rif fus	Derivative of JH2	3
OGIX	str	Protease-negative derivative of OG1-10	14
E. coli DH5α	recA1 endA1 gyrA96 thi-1 relA1 hsdR17 supE44 ΔlacU169 φ80 lacZΔM15		Invitrogen
Plasmids
pMG1	Gmr	65.1-kb conjugative plasmid from E. faecium strain	15
pAM225	tet	Tn917 was cloned in pBR325 with EcoRI fragment H of pAD1	23
pBluescriptSK	amp	E. coli cloning vector	Stratagene
Clone #71	amp	6-kbp HindIII fragment of pMG1 was cloned in pBluescriptSK	This study
p71E	amp	EcoRI deletion derivative of clone #71	This study
pMG226	amp erm	1.45-kbp ClaI fragment of Tn917 containing erm gene was cloned in pBluescript	This study
pMG227	amp erm	Internal fragment of 71ORF2 gene was cloned in pMG226	This study

^aTHB (Difco, Detroit, Mich.) was used for growth of E. faecalis and for broth mating. Luria-Bertani medium (19) was used for growth of E. coli. Agar plates were made by adding agar (1.5%) to the broth medium. Antibiotics were used at the following concentrations: erythromycin, 10 μg/ml; kanamycin, 500 μg/ml; gentamicin, 500 μg/ml; ampicillin, 100 μg/ml; fusidic acid, 25 μg/ml; and rifampin, 25 μg/ml.