Table 1.

Bacterial strains and plasmids used in this work.

Strain/plasmid	Characteristics	Source/Reference
E. coli DH5α	(F-φ80dlacZΔM15 Δ(lacZYA- argF)U169 endA1 recA1 hsdR17(rk- mk+) deoR thi-1 supE44 λ- gyrA96 relA1)	Invitrogen
L. lactis MG1363	L. lactis subsp. cremoris	[19]
LL-inlA+	L. lactis expressing L. monocytogenes inlA gene/Erya strain	[18]
LL-pIL253	L. lactis MG1363 harboring pIL253 plasmid/Erya strain	[18]
LL-pIL253 pValac:gfp+	L. lactis MG1363 harboring pIL253 and pValac:gfp plasmids/Erya-Cmb strain	Innocentin et al., [unpublished data]
LL-inlA+ pValac:gfp+	L. lactis expressing L. monocytogenes inlA gene and harbouring pValac:gfp/Erya-Cmb strain	Innocentin et al., [unpublished data]
pVAX1	Expression vector containing pCMV, MCS and BGH polyA/Ampc-Kmd	Invitrogen
TOPO	Cloning vector/Ampc	Invitrogen
TOPO:VAX1	TOPO vector containing the pCMV, MCS and BGH polyA fragment of pVAX/Ampc	This study
pXylT:CYT	Expression vector containing RepA/RepC replication origin/Cmb	[20]
pValac	Expression vector containing pCMV, MCS, BGH polyA, and RepA/RepC replication origin/Cmb	This study
pEGFP-N1	Expression vector containing the gfp gene/Ampc-Kmd	BD Bioscience, Clontech
pValac:gfp	pValac containing gfp ORF inserted in the XbaI/BamHI sites/Cmb	This study
pIL253	High-copy number lactococcal vector/Erya	[21]

^aEry: erythromycin resistance, ^bCm: chloramphenicol resistance, ^cAmp: ampicilin resistance, ^dKm: kanamicin resistance.