Table 1. Bacterial strains and plasmids used in this study.

Name	Descriptiona	Reference
E. faecalis
DS5	Cytolysin-positive clinical isolate	48
E1Sol	Gelatinase-positive commensal strain	49
CH188	Gelatinase- and cytolysin-negative clinical isolate	43
X98	Cytolysin-positive isolate	50
JH2-2	Gelatinase- and cytolysin-negative laboratory strain	21
T2	Gelatinase- and cytolysin-negative clinical isolate	42
MMH594	Gelatinase- and cytolysin-positive clinical isolate	51
V583	Gelatinase-positive clinical isolate	44
V583fsrB*	E. faecalis V583 with an amber point mutation in the fsrB codon that causes the loss of GBAP production; gelatinase-negative phenotype	Leanti La Rosa et al, submitted
V583ΔgelE	E. faecalis V583 gelE mutant; produces GBAP but has a gelatinase-negative phenotype	45
SL11	E. faecalis MMH594::pREG696 luxPgelE	This study
SL13	E. faecalis MMH594::pREG696 luxPfsrB	This study
JH2-2 CBS	E. faecalis JH2-2::pSL101cylR2R1Pcyl	This study
T2 CBS	E. faecalis T2::pSL101cylR2R1Pcyl	This study
V583fsrB* GBS	E. faecalis V583 fsrB*::pREG696 luxPgelE	This study
X98 pMG36c	E. faecalis ×98:: pMG36c	This study
X98 pCG	E. faecalis ×98:: pCG	This study
Plasmids
pSL101cylR2R1Pcyl	Spcr, contains the axe-txe cassette and the luxABCDE operon under the control of the Pcyl promoter and the regulatory genes cylR2 and cylR1	18
pREG696 luxPgelE	Spcr, contains the gelE promoter fused to the luxABCDE operon	18
pREG696 luxPfsrB	Spcr, contains the fsrB promoter fused to the luxABCDE operon	45
pMG36c	Camr,	52
pCG	Camr	53

^aSpc^r, spectinomycin resistance; Cam^r, chloramphenicol resistance.