TABLE 1.

Bacterial strains and plasmids used in this study

Bacterial strain or plasmid	Relevant propertya	Source or reference
Strains
E. coli TOP10	Cloning host	Invitrogen
E. coli Match1	Cloning host	Invitrogen
L. monocytogenes EGD-e	Wild type of serotype 1/2a for which the genome sequence is available	39
L. monocytogenes DG125A	L. monocytogenes EGD-e with in-frame deletion of the agrA gene	This work
L. monocytogenes DG119D	L. monocytogenes EGD-e with in-frame deletion of the agrD gene	This work
Plasmids
pGF-EM	Cmr Amr; 9.4-kb derivative of pCON-1 containing the 0.8-kb gfp gene of pKV111 and the erm gene of Tn917	33
pGID109	Kmr Amr; 4.4-kb derivative of pCR21-TOPO containing the 0.6-kp 3′ end of agrD and the 5′ end of agrC	This work
pGID112	Cmr Amr; 10.4-kb derivative of pGF-EM containing the 0.4-kb 5′ end of agrD	This work
pGID118	Kmr Amr; 4.3-kb derivative of pCR21-TOPO containing the 0.5-kp internal region of agrA	This work
pGID119	Cmr Amr; 9,4-kb derivative of pGID112 containing the 3′ end of agrD inserted into the XbaI/EcoRI site of pGID109	This work
pGID121	Cmr Amr; 10.6-kb derivative of pGF-EM containing the 0.6-kb 3′ end of agrC and the ATG of agrA	This work
pGID125	Cmr Amr; 9.3-kb derivative of pGID121 containing the internal region of agrA inserted into the XbaI/EcoRI site of pGID118	This work

^aKm^r, kanamycin resistant; Am^r, ampicillin resistant; Cm^r, chloramphenicol resistant.